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Maritime Dictionary




Second Half




Always Afloat


Always Accessible Always Afloat


Amsterdam-Antwerp-Rotterdam Area


A relative term used to describe the location of one object in relation to another, in which the object described is farther aft than the other. Thus, the mainmast is abaft the foremast (in back of).

Abaft the beam

Said of the bearing of an object which bears between the beam and the stern (further back than the ship's middle).

Abandon ship

Get away from the ship, as in an emergency.


The bearing of an object 90 degrees from ahead (in a line with the middle of the ship).

Able bodied seaman

The next grade above the beginning grade of ordinary seaman in the deck crew.


In the vessel (on the ship).


Above decks; without concealment of deceit (out in the open).


Abeam of (alongside of).


A bushing plate around a hole in which a pintle works.



Access Holes

Holes cut in ship's structure to permit entering or leaving various compartments.

Accommodation ladder

The portable steps from the gangway down to the waterline.


Hooks for the chains.


A solid piece of metal shaped like an acorn, and used to finish off the top of an upright in a railing contructed of pipe.


Address Commission

Added mass

The effective increase in mass of a hull, due to the entrained water, when in motion.

Added weight method

One method used in the calculation of a ship's damaged stability when it is partially fl ooded. It regards the water which has entered as an added weight, the basic hull envelope remaining. The other approach uses the concept of lost buoyancy.


Comes from the Arabic "Emir" or "Amir" which means "First commander" and "Al-bahr which means "the sea". Emir-al-barh evolved into Admiral.


Loose from the moorings (not tied or secured).


Aqueous Film Forming Foam


The hiring of a ship in whole or part




A term used for the largest dry bulkcarriers.


Arrival First Sea Pilot Station (Norway)


At, or towards the stern of a vessel. (Opposite to forward.)

Aft peak tank

A tank or compartment located abaft the aftmost watertight transverse bulkhead above propeller(s) and rudder (often used for fresh water or sea water ballast).

After body

The section aft of amidships.

After deck

A term applied to a deck aft to the midship portion of a vessel.

After frammes

Radiating cant frames fastened to transom plates.

After peak

A compartment just forward of the stern post. It is generally almost entirely below the load water line.

After peak bulkhead

A term applied to the first transverse bulkhead forward of the stern post. This bulkhead forms the forward boundary of the after-peak tank and should be made watertight.

After perpendicular

The vertical line through the intersection of the load water line and the after edge of the stern post. On submarines or ships having a similar stern, it is a vertical line passing through the points where the design waterline intersects the stern of the ship>

After rake

That part of the stern which overhangs the keel.


Nearest the stern.


Resting on the bottom.


All Going Well


Australian Hold Ladders


A call used in hailing a vessel or boat (hey!).


Admiralty Information Overlay

Air casing

A ring-shaped plate coaming surrounding the stack and fitted at the upper deck, just below the umbrella. It protects the deck structure from heat and helps ventilate the fireroom.

Air draught

The vertical distance from the summer waterline to the highest point in the ship, usually the top of a mast.

Air Hammer

Hammer driven by compressed air for riveting, or chipping. Sometimes called an air gun or "gun".

Air port

An opening in the side of a ship or a deck house, usually round in shape and fitted with a hinged frame in which a thick glass light is secured. The purpose of the air port is to provide light and ventilation to and vision from the interior.

Air tank

A metal air-tight tank built into a boat to insure flotation even when the boat is swamped.

Air-tight door

A door so constructed that, when closed, air cannot pass through. They are fitted in air locks.


As Low As Reasonable Practicable


To the leeward side (away from the wind).


Alert (pep it up!).

All hands

The entire crew.

All standing

To bring to a sudden stop.


A vessel's internal passageway or corridor.


Above the upper deck (above).


The position of a vessel when securely moored on a berth in port.


A step in a graving dock.


In the longitudinal, or fore-and-aft center of a ship. Halfway between stem and stern. The term is used to convey the idea of general locality but not that of definite extent.


(1) Midway (midpoint) between port and starboard sides of a vessel. (2) The midway point between the forward and aft perpendiculars.


Australian Maritime Safety Authority


Automated Mutual-Assistance Vessel Rescue System


A heavy steel device (of variable design) so shaped as to grip the sea bed to hold a vessel or offshore installation in a desired position.




Anchor bar

Wooden bar with an iron shod, wedge shaped end, used in prying the anchor or working the anchor or working the anchor chain. Also used to engage or disengage the wild-cat.

Anchor billboard

A structure on the deck of a vessel upon which the anchor is mounted when not in use.


Anchor billboard

Anchor cable

Chain or wire connecting a vessel to its anchor(s).

Anchor chain

Heavy, linked chain secured to an anchor for mooring or anchoring.

Anchor lights

The riding lights required to be carried by vessels at anchor.

Anchor stopper

A device to hold an anchor cable so as to prevent the anchor from running out or to relieve the strain at the inboard end.


Anchor stopper

Anchor watch

The detail on deck at night, when at anchor, to safeguard the vessel (not necessarily at the anchor; a general watch).


A place suitable for anchoring.

Anchor's aweigh

Said of the anchor when just clear of the bottom (leaving or moving).


Same as angle bar

Angle bar

A bar of angle-shaped section used as a stiffener and on riveted ships ties floors to the shell.

Angle clip

A short piece of angle bar.

Angle collar

Angle bent to fit a pipe, column, tank or stack, intersecting or projecting through a bulkhead or deck for the purposes of making a watertight or oiltight joint.


To heat a metal and to cool it in such a fashion as to toughen and soften it. Brass or copper is annealed by heating to a cherry red and dipping suddenly into water while hot. Iron or steel is slowly cooled from the heated condition to anneal.


Zinc or aluminium or some such alloy that is fixed to the hull of a vessel. They are "eaten" up by electrical currents moving from the vessel to the water. The anode is sacrificed to protect the metal hull of the vessel - without the anode, the hull plating would be disolved by electrolysis.


Antwerp-Hamburg Range

Antifouling (paint)

A marine paint composition containing toxic ingredients preventing or retarding marine underwater growth on the hull of a vessel.


The space provided between propeller and stern post for the propeller.


Animal & Plant Health Inspection Service


American Petroeum Institute


Objects protruding from the underwater section of a hull; e.g., bilge keels, rudders, stabilising fins, shaft brackets, etc.


Relatively small portions of a vessel projecting beyond its main outline, as shown by cross-sections and water-sections. The word applies to the following parts of the stern and stern post: the keel below its shell line, the rolling keel or fin, the rudder, rudder post, screw, bilge keel, struts, bossing and skeg.


Act to Prevent Pollution from Ships

Apron plate

A plate fitted in the continuation of the shell plating above the forecastle sheer strake at the stem. These plates are sometimes fitted one in each side of the stem, and serve as foundation for the bow mooring pipes.


Arrival Pilot Station


Asia Pacific Terminal Forum


Amsterdam-Rotterdam-Antwerp-Ghent Range


The principal axis member or spindle of a machine by which a motion of revolution is transmitted.

Arch piece

The curved portion of the stern frame over the screw aperture, joining the propeller post and stern post.


Automatic Radar Plotting Aid


On the shore (on land).


Annual Safety Inspection


To fit together small parts, in making a large section, or part.


The backward direction in the line of a vessel's centreline.


Any Time Day or Night Sundays and Holidays Included


Same as a beam


Transverse or across a vessel from side to side.


Across the ship, at right angles to the centreline.


Actual Times Used to Count


Various winches, pumps motors, engines, etc., required on a ship, as distinguished from main propulsive machinery (boilers and engines on a steam installation).

Auxiliary foundations

Foundations for condensers, distillers, evaporator pumps or any of the auxiliary machinery in the engine or boiler rooms.

Auxiliary machinery

Machinery other than the ship's main engines.


An order to stop or cease hauling (stop action at once).


Level with the water (water ready to, or slightly covering decks).


A canvas canopy secured over the ship's deck as a protection from the weather (covering).

Aye, aye, sir

The reply to an officer's order signifying that he is understood and will be obeyed (I understand).



Back bar

Used on the opposite side of a bosom bar.


To haul a shipment back over part of a route that it has already traveled; return movement of cargo, usually opposite from the direction of its primary cargo destination.


Bunker Adjustment Factor. A Fuel Surcharge expressed as a percentage added or subtracted from the freight amount reflecting the movement in the market place price for bunkers.


To throw water out of a boat; a yoke, as a ladder bail (rung).

Balanced frames

The midship frames that are of equal shap and square flanged. There are thirty or more on a cargo vessel, equally divided between starboard and port sides.

Balanced rudder

A rudder with its axis halfway between the forward and after edge.

Bale capacity

Capacity in hold to edge of frames and stiffeners; refl ects the stowage of bales or boxes.


(In cerpentry) a piece of timber from 4" to 10" square.


Any weight carried solely for the purpose of making the vessel more seaworthy. Ballast may be either portable or fixed, depending upn the condition of the ship. Fixed or permanent ballast in the form of sand, concrete, scrap or pig iron is usually fitted to overcome an inherent defect in stability or trim due to faulty design or changed character of service. Potrable ballast, usually in the form of water pumped into or out of the bottom, peak, or wing ballast tanks, is utilized to overcome a temporary defect in stability or trim due to faulty loading, damage, etc.


Ballast keel

A heavy keel fitted to vessels to lower the center of gravity and improve stability.

Ballast tanks

Double bottoms for carrying water ballast and capable of being flooded or pumped out at will.


Cylindrical structure built up to armor plates extending from the protected deck of a war vessel to the lower side of the turret shelf plate. They form protective enclosures in which are located the turret stools, shell stowage flats and ammunition hoisting gear for the turrets.


Bareboat Charter Owners lease a specific ship and control its technical management and commercial operations only.


A craft of full body and heavy construction designed gor the carriage of cargo but having no machinery for self-propulsion.


Small marine growth which attaches itself to a vessel's hull in large numbers, often greatly retarding her speed.

Base line

A horizontal fore and aft reference line for vertical measurements. This line is perpendicular to the vertical center line. A horizontal transverse reference line for vertical measurements. This is line is perpendicular to the vertical center line. A horizontal transverse reference line for vertical measuremnts. This line is perpendicular to both the vertical center line and fore-and-aft base line.



A narrow strip of wood for fairing in lines. Also a stripof wood to fasten objects together. A strip of paulins in place. (Verb) To secure by means of battens, as to "batten down a hatch".

Batten down

To make watertight. Said of hatches and cargo (tie up or secure).

Battens, cargo

A tern applied to the planks that are fitted to the inside of the frames in a hold to keep the cargo away from the shell plating, the strips of wood or steel used to prevent shifting of cargo.


Before Breaking Bulk


Both Dates Inclusive


Bunker Delivery Note


A derelict seaman found unemployed on the waterfront, especially in a foreign country (seaman without a ship).


(1) The registered breadth of a vessel, measured at the outside of the hull amidships, or at its greatest breadth. (2) A transverse structural member supporting a deck and/or strengthening a hull.


Beam knees

Angular fittings which connect beams and frames together.

Beam line

The line showing the top of the frame line.

Beam plate angles

A beam made from a flat plate, with the flange bent at right angles by an angle-bending machine.

Beam wind

A wind at right angles to a vessel's course (wind blowing at the ship's side.)

Bear a hand

To assist or help.

Bear down

To approach (overtake or come up to).


A term applied to foundations, particularly those having vertical web plates themselves are called bearers.


The direction of an object (with reference to you, your ship, another object).


A sailing vessel dead in the water due to lack of wind (not moving).


A rope eye for the hook of a block. A rope grommet used in place of a rowlock. Also, a small piece of rope with an eye in each end to hold the feet of a sprit to the mast. In general any small rope or strap used as a handle.

Bed plate

A structure fitted for support of the feet of the engine columns, as well as to provide support for crankshaft bearings. It also helps distribute engine weight and stresses to the ship's structure. The bed plate consists of a series of transverse girders, connecting fore-and-aft members or girders.


Biological Exposure Indices


To make fast as to a pin or cleat. To rescind an order (tie up).

Belaying pin

A wooden or iron pin fitting into a rail upon which to secure ropes.

Bell suction

The flared open end of a cargo pipeline which is situated at close tolerances to the bottom of a liquid cargo tank.


see Ships Time

Belly strap

A rope passed around (center) a boat or other object for hanging.


Undernearth the surface of the water. Undernearth a deck or decks


The twisting or turning of a rope so as to fasten it to some object, as a spar or ring.

Bending rolls

Large machine used to give curvature to plates by passage in contact with three rolls.

Bending slab

Heavy cast-iron blocks with square or round holes for "dogging down" arranged to form a large solid floor on which frames and structural members are bent and formed.


Both Ends (Load & Discharge Ports)


Best Environmental Practice


A place for a ship. The distance from frame line to frame line. A term applied to a bed or a place to sleep. Berths, as a rule, are permanently built into the structure of the staterooms or conpartments. They are constructed singly and also in tiers of two or three, one above the other. When single, drawers for stowing clothing are often built in underneath. Tiers of berths constructed of pipe are commonly installed in the crew space.

Berth term

Shipped under a rate that does not include the cost of loading or unloading.

Between decks

The space between any two, not necessarily adjacent, decks. Frequently expressed as "Tween Decks".


Any angle other than 90o which one surface makes with another. Also to bevel a beam, flange, or plate for vee welding, to tilt a girder to make the sheer bevel.

Bevel square

A device that can be used to make a close bevel, less than 90o, or an open bevel, more than 90o.


Both Inclusive


Formed by bringing the end of a rope around, near to, or across its own part.


(1) Intersection or curved transition of bottom and sides of a hull. (2) Lowest points within hull compartments where liquids may accumulate.


Bilge blocks

Supporting blocks used under bilge for support during construction or drydocking.

Bilge bracket

Vertical transverse plate located beneath side frames in the area of the bilge and between inner and outer bottoms.

Bilge keel

Non-retractable elongated longitudinal fin protruding from the bilge used to reduce rolling.

bilge keels

Bilge keel

Bilge plates

The curved shell plates that fit the bilge.

Bilge pump

Pump for removing bilge water.

Bilge strake

Line of shell plating at the bilge between bottom and side plating.

Bilge well

A bilge well is generally located in the lowest part of the compartment. It is used for drainage and is generally shaped like a box, and fitted to the underside of the inner bottom, with a strainer on top.


The lowest portion of a ship inside the hull, considering the inner bottom where fitted as the bottom hull limit.


Same a bilge

Bill of lading

A document that establishes the terms of contract between a shipper and a trasportation company. It serves as a document title, a contract of carriage, and a receipt for goods.


Baltic & International Maritime Council


A walled enclosure built on the deck of a barge for the purpose of retaining cargo; also called a pen or cargo box.


A stand or case for housing a compass so that it may be conveniently consulted. Binnacles differ in shape and size according to where used and the size of the compass to be accpmmodated. A binnacle for a ship's navigating compass consists essentially for a pedestal at whose upper and is a bowl-shaped receptacle having a sliding hood-like cover. This receptacle accommodates the gimbals supporting the compass. Compensating binnacles are provided with brackets or arms on either side, starboard and port, for supporting and securing the iron cylinders or spheres used to counteract the quadrantal error due to the earth's magnetization of the vessel. This type of binnacle is usually placed immediately in front of the steering wheel, having its vertical axis in the vertical plane of the fore-and-aft center-line of the vessel.

Birth marks

Same as Plimsoll marks.

Bitter end

(Nautical). The inboard end of a vessel's anchor chain which is made fast in the chain locker


Twin stout posts welded to the deck to which mooring lines are fastened.



A black, tar-like composition largely of bitumen or asphalt and containing such other ingredients as rosin, Portland cement, slaked lime, petroleum, etc. It is used as a protective coating in ballast and trimming tanks, chain lockers, shaft alleys, etc.

BL (1)


BL (2)

(Bill of Lading) A document signed by the carrier which acts as a receipt and evidence of title to the cargo.

Black gang

Member of the engine-room force, which included the engineers, firemen, oilers, and wipers.

Blank flange

A flange which is not drilled but which is otherwise complete.


A term applied to plugs screwed into the bottom of a ship to provide for drainage of the compartments when the vessel is in dry dock.


Bulk Liquids and Gases


The name given a pulley or sheave, or system of pulleys or sheaves mounted in a frame, and used to multiply power when moving objects by means of ropes run over the sheaves. Single, double or triple-when used with the word "block" indicate the number of sheaves it contains.

Block and block

Same as two blocks.

Block and tackle

(Block and Falls). The complete unit of two or more blocks rove up with an adequate amount of rope.




Best Management Practices


Bridge Navigational Watch Alarm System


A purchase (block and tackle) for hoisting a boat to its davits.


Bunker on Board

Body plan

A pair of half transverse and elevations, with a common vertical center line. The right side gives the ship as seen from ahead, the left side from astern. Water lines, buttock and bow lines, diagonal lines, etc., are shown.

Body plan


Bureau of Ocean Energy Management, Regulation and Enforcement


Best Offer


Any vessel, container or receptacle that is capable of generating steam by the internal or external application of heat. There are two general classes of boilers. I.E., fire-tube and water-tube.

Boiler casing

A wall protecting the different deck spaces from the heat of the boiler room.

Boiler chocks

Stay braces which prevent fore and aft movement of boilers.

Boiler foundation

The structure upon which the boiler is secured. It generally consists of girders built up from plates and shapes. In a cylindrical boiler the athwartship girders are often called saddles.

Boiler room

A compartment in the middle or after section of a vessel where the boilers are placed.


The equivalent of a vessel's mooring bitts used onshore.


Bollard pull

The static pulling force of a tugboat measured in pounds.

Bolster plate

A piece of plate adjoining the hawse hole, to prevent the chafing of the ship's bow. A plate foe support like a pillow or cushion.

Bond port

Port of a vessel's initial customs entry to any country; also known as first port of call.

Bonded warehouse

A warehouse authorized by customs authorities for storage of goods on which payment of duties is deferred until the goods are removed.

Booby hatch

The cover of a scuttle-way or small hatchway, such as that which leads to the forecastle or fore peak of a vessel.


A term applied to a spar used in handling cargo, or as the lower piece of a fore-and-aft sail.

Boom cradle

A rest for a cargo-boom when lowered for securing for sea.

Boom rest

A support for a boom when the boom is not in use.

Boom step

A socket for end of boom.

Boom table

An outrigger attached to the mast, or a structure built up around a mast from the deck, to support the heel bearings for booms. Boom tables are necessary to provide working clearances when a number of booms are installd on one mast.


Durable paint coating applied to a hull between the light and loaded waterlines.


Special resistant paint or paints used to coat that portion of a vessel between light and load lines. Also the area to which this paint is applied.

Bort flange

A protruding flange above a port to keep drip from entering.


Shortening of the old term "boatswain," an unlicensed member of the crew who supervises the work of the deck men under direction of the first mate.

Bos'n's chair

The piece of board on which a man working aloft is swung.

Bos'n's chestb

The deck chest in which the bos'n keeps his deck gear.

Bos'n's lockerb

The locker in which the bos'n keeps his deck gear.


The inside of an angle bar.

Bosom barb

One angle fitted inside another.

Bosom plate

A plate bar or angle fitted to an angle bar to connect the ends of two angles.


The part of the propeller to which blades are attached. Also the aparture in the stern frame where propeller shaft enters.

Boss frame

A frame bent around to fit the bose in way of the stern tube or shaft.

Boss plate

The plate fitted around the boss of a propeller post or around the curved frames in way of stern tubes.


Hydrodynamically faired outboard portion of hull plating surrounding and supporting propeller shafting. In a single-screw vessel the bossing is integral to a centreline skeg.

Bottom plating

That part of the shell plating which is below the water line.

Bottom, outer

A term applied to the bottom shell plating in a double bottom ship.

Bounding angle

A steel angle used for reinforcement at the junction of two steel plates.

Bounding bar

A bar connecting the edges of a bulkhead to tank top, shell, decks, or another bulkhead.


The fore end or a ship.


Bow door

Watertight hinged door in the fore end of a Ro-Ro vessel through which vehicles and cargo may be loaded or discharged

Bow door

Bow linesb

Curves representing a vertical section of the bow end of a ship. Similar curves in aft part of hull are buttock lines.

Bow rudderb

A rudder placed at the bottom of the forward stem and maneuvered from the fore peak.

Bow thruster

A propulsor installed near the bow to provide a transverse thrust component enhancing manoeuvrability.

Bow thruster


A spar extending forward from the stem.

Boxed end

The end of a barge which is squared for the full depth and width of the hull.

Boxing the compass

Calling names of the points of the compass in order.


Bridge Procedures Guide


Barge Particulars Questionnaire


A steel plate, commonly with a reinforcing flange, used to stiffen or tie beam angles to bulkheads frames to longitudinals, etc.


To heat and join by means of hard solder (spelter). This may be brass, bronze, or other alloys.


The side-to-side measurements of a vessel at any given place.

Breadth extreme

The maximum breadth measured over plating or planking, including heading or enders.

Breadth, molded

See Molded Breadth.

Breadth, registered

Measured amidships at its greatest breadth to outside of plating.


Of poop or forecastle. The point at which the partial poop or forcastle deck are discontinued.

Break ground

Said of anchor when it lifts clear of the bottom.


Loose, noncontainerized cargo stowed directly into a ship's hold.


A small cask for fresh water carried in ship's boats. A sea (wave) with a curl on the crest.


A term applied to plates fitted on a forward weather deck to form a V-shaped shield against water that is shipped over the bow.


Cleaning the barnacles, paint, etc., from a ship's bottom with a blow torch.

Breast beam

The transverse beam nearest to midship on the poop and forecastle deck.

Breast hook

Ahorizontal plate secured across the fore peak of a vessel to tie the fore-peak frames together and unit the bow.

Breast rail

The upper rail of a balcony on the quarter deck.


Horizontal plate brackets of generally triangular form connecting port and starboard side stringers and bow plating at the stem.


Elevated centre dedicated to the control and navigation of the vessel. [Alt. Navigating bridge or wheelhouse.]

Bridge house

The erection or superstructure fitted about amidship on the upper deck of a ship. The officer's quarters, staterooms and accommodations are usually in the bridge house.

Bridge wing(s)

Lateral (open or enclosed) extension(s) to a vessel's bridge to permit direct vision beyond the hull side.

Bridge, navigating or flying

The uppermost platform erected at the level of the top of the pilot house. It generally consists of a narrow walkway supported by stan-chions, running from one side of the ship to the other and the space over the top of the pilot house. A duplicate set of navigating instruments and controls for the steering gear and engine room signals are installed on the flying bridge so that the ship may be navigated in good weather from this platform. Awnings erected on stanchions and weather cloths fitted to the railing give protection against sun and wind.


A high transverse platform, often forming the top of a bridge house, extending from side to side of the ship, and from whick a good view of the weather deck may be had. An enclosed space called the pilot house is erected on the bridge in which are installed the navigating instruments, such as the compass and binnacle, the control for the steering apparatus, and the signals to the engine room. While the pilot house is generally entended to include a chartroom and sometimes staterooms, a clear passageway should be left around it. As the operation of the ship is directed from the bridge or flying bridge above it, there should also be clear, open passage from one side of the vessel to the other.


A V-shaped chain, wire, or rope attached to a vessel being towed to which the towline is connected.


Bright work

Brass work, polished (also varnished wood work in yachts).


Bunkers Remaining on Board


A person who arranges for transportation of loads for a percentage of the revenue from the load.


A small curved angle or flanged plate fitted on the outside of the shell of a ship over an air port to prevent water running down the ship's side from entering the open port. Also called a watershed.


Barge Safety Guide



BSS 1/1

Basis 1 Port to 1 Port


Berth Terms

Buck frame

A transverse truss.

Buckle plateb

A plate that has warped from its original shape also a plate that is wider at the center than at the end.


A term applied to a floating object that is moored or anchored so that it remains at one place. Budys are used for marking the places on the water where a ship is sunk, where reefs are below, where the edges of the channel are, or to provide means for mooring ship at a desired position.


Ability to float, the supporting effort exerted by a liquid (usaually water) upon the surface of a boly wholly or partially immersed.

Building slip

An inclined launching berth where the ship is built.

Build-operate-transfer (BOT)

A form of concession where a private party or consortium agrees to finance, construct, operate and maintain a facility for a specific period and transfer the facility to the concerned government or port authority after the term of the concession. The ownership of the concession area (port land) remains with the government or port authority during the entire concession period. the concessionaire bears the commercial risk of operating the facility.

Bulb angle

Or bulb angle bar. An angle with one edge having a bulb or swell.

Bulb plate

A narrow plate generally of mild steel, rolled with a bulb or swell along one of its edges. Used for hatch coamings, built up beams, etc.

Bulb tee

A Tee bar with toe of web reinforced.


Same as bilge.

Bulk cargo

Cargo shipped in loose condition and of a homogeneous nature.

Bulk carrier

Vessel designed for the transportation of dry loose homogeneous cargoes in bulk in self-trimming holds and constructed to sustain the heavy concentrated weight distribution of the cargoes.

Bulk carrier


(1) A vertical structural partition dividing a vessel's interior into various compartments for strength and safety purposes; (termed strength bulkhead). (2) Term applied to vertical partition walls (non-structural) subdividing the interior of a vessel into compartments.


Bulkhead bounding: bar

A bar used for the purpose of connecting the edges of a bulkhead to the tank top, shell, deck, or to another bulkhead. Angle bars are generally used for this purpose, as both flanges are easily calked.

Bulkhead deck

Uppermost deck at which transverse watertight bulkheads terminate

Bulkhead deck

Bulkhead sluice

An opening cut in a bulkhead just above the tank top connecting angle, and fitted with a valve which may be operated from the deck above.

Bulkhead stiffeners

A term applied to the beams or girders attached to a bulkhead for the purpose of supporting it under pressure and holding it in shape. Vertical stiffenera are most commonly used, but horizontal stiffeners or a combination of both may be used.

Bull riveting

Driving rivets by squeezing them with a high powered air or hydraulic machine.

Bullnosed bow

Bow with large rounded bow point underneath water line.


Barrier of stiffened plating at the outboard edge of the main or upper deck to prevent or inhibit entry of the sea. Bulwarks may be additionally employed at the forward edges of superstructure decks in lieu of safety railings as a barrier to wind and spray.


Bulwark stay

A brace extending from the deck to a point near the top of the bulwark, to keep it rigid.


This is the assembly of pieces of cargo, secured into one manageable unit. This is a very flexible description; a rule of thumb is to present cargo at a size easily handled by a large (20 ton) fork lift truck.


Built-in bed aboard ship.


Compartment for the storage of oil or other fuel.

Bunker stays

A brace extending from the deck to a point near the top of the bulwark, to keep it rigid.


Name given for vessels Fuel and Diesel Oil supplies (Originates from coal bunkers)


A stationary floating object used as an aid for navigation.


Ability to float, lifting power when immersed.

Burr edge

The rough uneven edge of a punched or burnt hole or plate.

Butt joint

A joint made by fitting two pieces squarely together on their edges, which is then welded or butt strapped.

Butt strap

A bar or plate used to fasten two or more objects together with their edges butted.


A washing process used to gas free or clean a cargo tank, employing hot water or chemicals, sprayed through a patented rotating nozzle.

Butterworth opening

a deck access opening with bolted cover, designed for butterworth operations.


Counter. The rounded-in overhanging part on each side of the stern in front of the rudder, merging undernearth into the run.

Buttock lines

The curves shown by taking a vertical longitudinal section of the after part of a ship's hull, parallel to the keel.


A cast or fabricated deck item, usually round, that is used to thread cables between vessels when they are made-up.


Brackish Water Arrival Draft

By the board

Overboard (over the side).

By the head

Deeper forward (front end deepest in water).

By the Run

To let go altogether.



Clean Air Act


The captain's quarters. The enclosed space of decked-over small boat.


A chain or line (rope) bent to the anchor.

Cable layer

Vessel designed for the laying and repair of seabed telecommunication cables.

Cable layer

Cable locker

Compartment located forward to store the anchor cable.


The same as hawser-laid.


100 fathoms or 600 feet (6 feet to a fathom).


Shipments between ports of a single nation, frequently reserved to national flag vessels of that nation.


To tighten a lap or other seam with a chisel tool, either ny hand or meckanically.


A wind or force less than one knot (knot 1 nautical mile per hour).


Catenary Anchor Leg Mooring


A projecting part of a wheel or other simple moving piece in machinery, so shaped as to give predetermined variable motion to another piece against which it acts, in repeating cycles.


Court Appointed Monitor


Transverse convex curvature of exposed decks to accelerate runoff.


(In engineering) a decked vessel having great stability designed for use in the lifting of sunken vessel or structures. A submersible float used for the same purpose by submerging, attaching, and pumping out.


The inclination of an object from the perpendicular. As a verb, to turn anything so that it does not stand square to a given object.

Cant beam

Any of the beams supporting the deck plating or planking in the overhanging part of the stern of a vessel. They radiate in fan shape from the transom beam to cant frames.

Cant body

That portion of a vessel's boly either forward or aft in which the planes of the frames are not at right angles to the center line of the ship.

Cant frame

Hull side frame not aligned perpendicular to the vessel's centreline.

Cant frames

The frame (generally bulb angles) at the end of a ship which are cented, that is, which rise obliquely from the keel.


A term applied to large cargo vessels that cannot transit either the Panama or Suez Canals. They are usually of the order of 120 000-180 000 DWT.


A ship is said to capsize when it loses transverse stability and rolls over and sinks.




Steel warping drum rotating on a vertical axis for the handling of mooring lines and optionally anchor cable.


Capstan, steam

A vertical drum or barrel operated by a steam engine and used for handing heavy anchor chains, heavy hawsers, etc. The engine is usually non-reversing and transmites its power to the capstan shaft through a worm and worm sheel. The drum is fitted with pawls to prevent overhauling under the strain of the hawser or chain when the power is shut off. The engine may be disconnected and the capstan operated by hand through the medium of capstan bars.


A wooden bar which may be shipped in the capstan head for heaving around by hand (to heave up anchor or heavy objects by manpower).

Captain of the Head

A guy who gets Head (toilet) cleaning detail.

Car carrier

Vessel designed for the delivery transportation of road vehicles.

Car carrier


California Air Resources Board

Cardinal pointsb

The four principal points of the compass North, East, South and West.


Merchandise or goods accepted for transportation by ship.

Cargo battens

Strips of wood used to keep cargo away from the steel hull.

Cargo boom

A heavy boom used in handling cargo.

Cargo door

Watertight door in the hull side through which cargo may be loaded or discharged.

Cargo door

Cargo hatch

Large opening in the dec to permit loading of cargo.

Cargo port

An opening, provided with a watertight cover or door, in the side of a vessels of two or more decks, through which the cargo is received and discharged.

Carlines (carlings)

A short beam running fore and aft between or under transverse deck beams. Also called headers when they support the ends of interrupted deck beams.


Any person or entity who, in a contract of carriage, undertakes to perform or to procure the performance of carriage by sea, inland waterway, rail, road, air, or by a combination of such modes.


Intraport or local hauling of cargo by drays or trucks (also refferd to as drayage).

Carvel built

A type of plating made flush be vee butt welding or butt strap riveting.


Condition Assessment Scheme

Case joint

A kind of plate joint by which an overlap can gradually be made flush. This is done with the aid of liners, and is used on the bow and stern to give the vessel a finer trim.


The extra case or bulkhead built around the ship's funnel to protect the decks from heat. See Air Casing.

Cast off

To let go.

Cathodic protection

Sacrificial or impressed current system of corrosion protection of hull, tanks and piping.

Cathodic protection


To fill in the seams with cotton or oakum.


One who caulks.


The formation of bubbles on an aerofoil section in areas of reduced pressure. Can occur on heavily loaded ship propellers.



Collective Bargaining Agreement


Cubic Feet


Cubic Meter


Customs Border Protection


Corporate Compliance Manager


Central Commission for Navigation on the Rhine


Close Circuit Television


The inside skin of a vessel between decks, or in a small vessel from the deck beams to bilge.

Cellular container ship

Container vessel having specially designed vertical cell guides for the accommodation of standard size containers thereby precluding movement and lashing.

Cellular container ship

Cellular double bottomb

A term applied where the double bottom is divided into numerous rectangular compartments by the floors and longitudinals.

Center lineb

A horizontal fore- and -aft reference line for athwartship measurements, dividing the ship into two symmetrical halves. A vertical reference line in the center of the body plan, midship section or other sections.

Center line bulkhead

A fore-and-aft or longitudinal bulkhead erected on the center line or in the same plane as the keel. Also a reference line scrived on a transverse bulkhead to indicate the center of the ship.

Centre of buoyancy (CB)

That point through which the buoyancy force acts. It is defi ned in space by its longitudinal, vertical and transverse (respectively, LCB, VCB and TCB) position relative to a set of orthogonal axes. It is also the centroid of volume of the displaced water.

Centre of buoyancy (CB)

Centre of flotation (CF)

The centroid of area of a waterplane. A small weight added, or removed, from the ship vertically in line with the CF will cause a change of draught without heel or trim. For a symmetrical ship the CF will be on the centerline and its position is given relative to amidships.

Centre of flotation (CF)

Centre of gravity (CG)

The point through which the force due to gravity, that is the weight of the body, acts. Its position is defi ned in a similar way to the centre of buoyancy and is very important in calculations of stability.

Centre of gravity (CG)


The longitudinal vertical plane of a vessel.


China Focus Group


Chief Financial Officer


Code of Federal Regulations

CFR (or C&F)

Cost and Freight


To wear the surface of a rope by rubbing against a solid object.

Chafing gear

A guard of canvas or rope put around spars, mooring lines, or rigging to prevent them from wearing out by rubbing against something.

Chafing plate

A bent plate used in minimizing chafing of ropes, as at hatches.

Chain locker

The compartment for storing the anchor chains, located near the hawse pipes in the bow of the ship.

Chain locker

Chain locker manger

See Manager

Chain locker pipe

The iron-bound opening or section of pipe loading from the chain locker to the deck, through which the chain cable passes.

Chain riveting

Two or more rows of rivets spaces so that the rivets in one row are opposite those in adjacent row.


Anchor chains


A bevel surgace formed by cutting away the angle of two faces of a piece of wood or metal.

Charley Noble

The galley smoke-pipe (cook's stove pipe), named after The English sea captain who was noted for the scrupulous cleanliness and shine of the brass aboard his ship.

Chart house

Small room adjacent to the bridge for charts and navigating instruments.

Chart room

A small room adjacent to the Pilot House in which charts and navigating instruments are located.


A frame with wheels and container locking devices to secure the container for movement.


To ease off gradually (go slower and move carefully).

Check lines

Used in shaping plates, etc., to make sure that the template have not changed in size by shrinking or expending


The bilgeways, or curve of the bilges.

Chemical carrier (Tanker)

Vessel designed specifically for the transportation of volatile, poisonous or corrosive liquids in specially constructed tanks.

Chemical carrier (Tanker)


The crew's term for the chief engineer.

Chief mate

Another term for first mate.


(In naval architecture) a small piece of wood used to make good any deficiency in a piece of tember, frame etc.


Chock boat

A cradle or support for a lifeboat.

Chock roller

A chock with a sheave to prevent chafing of ropes.


Deck fittings for mooring line to pass through.


The falls foul in a block. The falls may be chocked or jammed intentionally for a temporary securing (holding).


Charterers Option




Concentrated Inspection Campaign


Cost, Insurance & Freight. Seller pays all these costs to a nominated port or place of discharge.

Classification societies

Organisations which set standards for design and construction of vessels and integral machinery amongst much else. Lloyd's Register of Shipping, Bureau Veritas, Registro Italiano Navale, American Bureau of Shipping, Det Norske Veritas, Germanischer Lloyd, Nippon Kaiji Kyokai, Russian Maritime Register of Shipping, Hellenic Register of Shipping, Polish Register of Shipping, Croatian Register of Shipping, China Corporation Register of Shipping, China Classification Society, Korean Register of Shipping, Turk Loydu, Biro Klasifikasi Indonesia, Registo Internacional Naval, Indian Register of Shipping, International Naval Surveys Bureau, Asia Classification Society, Brazilian Register of Shipping, International Register of Shipping, Ships Classification Malaysia, Dromon Bureau of Shipping, Iranian Classification Society

Cleaning in transit

The stopping of articles (such as farm products) for cleaning at a point between the point of origin and destination.


The size beyond which vessels, cars, or loads cannot pass through, under, or over bridges, tunnels, highways, and so forth.


A metal fitting having two projecting arms or horns to which a halyard or other rope is belayed. The deck, side plating, a stanchion, or other convenient structure serves as a support for securing the cleat.

Clinchimg pan

A flat plate for clinching nails. (used in the mold loft.)


A 4" to 6" angle bar welded temporarily to floors, plates, webs, etc. It is used as a holdfast which, with the aid of a bolt, pulls objects up close in fitting. Also, short lengths of bar, generally angle, used to attached and connect the various members of the ship structure.

Clipper bow

A bow with an exterme forward rake, once familiar on sailing vessels.

Close butt

A joint fitted clese by griding, pulled tight by clips, and welded.

Club foot

The flattened, broadened after end of the stern foot.


Course Made Good


Common Marine Inspection Document


Contract of Affreightment Owners agree to accept a cost per revenue ton for cargo carried on a specific number of voyages.


Contract of Affreightment Charter Party


Strictly speaking, coamings are the fore and aft framing in hatchways and scuttles, while the athwartship pieces are called head ladges, but the name coaming is commonly applied to all raised framework about deck openings. Coamings prevent water from running below, as well as strengthen the deck about the hatches.


Close of Business


The well of a sailing vessel, especially a small boat, for the wheel and steerman.


Cash On Delivery

Coeffi cients of fineness

These relate to the underwater form and give a broad indication of the hull shape. They are the ratios of certain areas and volumes to their circumscribing rectangles or prisms.


A small space left open between two bulkheads as an air space, to protect another bulkhead from heat, fidre hazard or collision.


Coffin plate

The plate used on an enclosed twin bossing, named for its shape. In reality it is inverted boss plate.


Course Over Ground


Carriage of Goods by Sea Act


To lay down rope in circular turns.


A system of small diameter pipes installed inside a liquid cargo tank for the purpose of heating the cargo by means of hot oil or steam.


A ring used around a pipe or mast, or a flat plate made to fit around a girder or beam passing through a bulkhead. They serve to make various spaces watertight.

Collision bulkhead

A watertight bulkhead approximately 25′ aft of the bow, extending from the keel to the shelter deck. This bulkhead prevents the entire ship from being flooded in case of a collision.

Collision bulkhead

Collision mat

A large mat used to close an aperture in a aperture in a vessel's side resulting from a collision.


The national ensign.


A convex curvature of the rake sides of a barge that produces a narrower beam at the headlog than the beam of the hull.

Coming around

To bring a sailing vessel into the wind and change to another tack. One who is influenced to a change of opinion.


A covering over the top of a companionway.


A set of steps or ladder leading up to a deck from below.


A subvision of space or room in a ship.

Compass, magnetic

The compass is the most important instrument of navigation in use on board ship, the path of a ship through the water depending upon the efficient.

Composite vessel

A vessel with a steel frame and wooden hull and decks


Sub-Committee on Radiocommunciations and Search and Rescue


The Oil Companies' European Organisation for Environment, Health and Safety


An arrangement whereby a private party (concessionaire) leases assets from an authorized public entity for an extended period and has responsibility for financing specified new fixed investments during the period and for providing specified services associated with the assets; in return, the concessionaire receives specified revenues from the opration of the ssets; the assets revert to the public sector at expiration of the contract.

Conning tower

Protective structure built up of armor plates and having verious shapes and sizes.




In some countries, this fee is levied to retain upkeep of the approaches to waterways and canals.


Cargo consisting of shipments of two or more shippers or suppliers. Container load shipments may be consolidated for one or more consignees.

Container vessel

Vessel designed specifically for the transportation of standard size containers within the hull and on deck.


Cargo that is prohibited.


Custom Of Port

Cork fenders

A fender made of granulated cork and covered with woven tarred stuff.


Having a series of wrinkles or grooves arranged so as to produce stiffness.

Corrugated bulkhead

A bulkhead made from plates of corrugated metal or by flat plates alternately attached to the opposite flanges of the bulkhead stiffeners. Corrugated metal bulkheads are used around staterooms and quarters. Corrugated cargo hold bulkheads are generally constructed of flat plate alternately attached to opposite flanges of the stiffeners.


Captain of the Port


The part of a ship's stern which overhangs the stern post.


Countersunk hole

A hole tapered or beveled around its edge to allow a rivet or bolt head to seat flush with or below the surface of the bolts object.

Countersunk rivet

A rivet driven flush on one or both sides.


The hood shaped top of a ventilator pipe.

CP (or C/P)

Charter Party


Closest Point of Approach


Charterers Pay Dues


Cardio Pulmonary Resuscitation


Carriage Paid To


Customary Quick Dispatch


A framing built up on the ways and in which the ship rests while being launched.


A cup-shaped depression in a weld. The are tends to push the molten metal away from the center of the point being welded, thus forming the crater.

Crew's gangway

Used on oil tankers. A elevated runway from poop to midship, and midship, and midship to forecastle deck. It affords means of safe passage for crew members when deck is awash in stormy weather.


Foundations of heavy blocks and timbers for supporting a vessel during construction.




Cargo Remaining on Board

Cross curves of stability

A series of curves showing how a ship's transverse stability varies, with displacement, for a range of heel angles. Curve of statical stability. A plot showing how the righting lever experienced by a ship varies with angle as the ship is rotated about a fore and aft axis. It defi nes a ship's stability at large angles. Also known as the GZ curve.


A pipeline that crosses over a tank providing a transit for cargo without tying into the vessel.

Crossing the line

Crossing the Equator.


A temporary horizontal timber brace to hold a frame in position. Cross-spalls are replaced later by the deck beams.


Term sometimes used denoting the round-up or camber of a deck. The crown of an anchor is located where the arms are welded to the shank.

Crown's nest

A lookout station attached to or near the head of a mast.

Crow's nest

The platform or tub on the mast for the look-out.


Same as breast hooks, but fitted at the after end.


Convention for Safe Containers


Cargo Securing Manual


Continuous Synopsis Record


Code of Safe Practice for Stowage & Securing Cargo




Carbon Task Force


Container Fitted


Cargo Transport Unit

Custom broker

A person or firm, licensed by the customs authority of their country when required, engaged in entering and clearing goods through customs for a client (importer).


A govenrment office where duties are paid, documents filed, and so forth, on foreign shipments.


The forward edge of the stem or prow of a vessel at the water level.


The foremost part of the stem, cutting the water as the vessel forges ahead.


Clean Water Act

Cyclodial propulsion system

A system of vertical blades that have taken the place of propellers for propulsion in some applications. Generically referred to as a "tractor system".




Drug & Alcohol


A piece of timber that is fastened to the poppets of the bilgeway and crosses them diagonally to keep them together. Dagger applies to anything that stands in a diagonal position.

Dagger plank

One of the planks whick unite the headsof the poppets or stepping-up pieces of the cradle on which the vessel rests in launching.


A material made of tarred rope fibers obtained from scrap rope, used for calking seams in a wooden deck. It is also used for calking around pipes.


Days all Purposes (Total days for loading & discharging)


A curved metal spar for handling a boat or other heavy objects.



A set of cranes or radial arms on the gunwale of a ship, from whick are suspended the lifeboats.


Deck Decompression Chamber


Delivered Duty Paid.


Delivered Duty unpaid.


Design and Equipment

Dead ahead

Directly ahead on the extension of the ship's fore and aft line.

Dead flat

The flat-surfaced midship section of a vessel on the sides above the bilge, or on the bottom below the bilge.

Dead light

Steel disc, that is dogged down over a porthole to secure against breakage of the glass and to prevent light from showing through.


Dead rise

The upward slope of a ship's bottom from the keel to the bilge. This rise is to give drainage of oil or water toward the center of the ship.


A shutter placed over a cabin window in stormy weather to protect the glass against the waves.


Steel or alloy cover plate fitted internally to portholes for protection against water ingress in case of glass failure.


An object, such as an anchor, piling, or concrete block, buried on shore.


Transverse inclination of the hull bottom from keel to bilge. [Alt rise of floor.]


The total weight of cargo, fuel, water, stores, passengers and crew and their effects that a ship can carry when at her designed full-load draft.

Deadweight tonnage

The cargo capacity of a vessel.


A platform or horizontal floor which extends from side to sede of a vessel.

Deck beam dimensions

The molding of a deck beam is its vertied dimension. Its siding is its horizontal dimension.

Deck button

A round, steel fitting affixed to a vessel's deck, designed to secure or guide cables for making up barge tows.

Deck button

Deck height

Vertical distance between moulded lines of 2 adjacent decks. [Alt deck interval.]

Deck house

A small house on the after or midship section of a vessel.

Deck lashing strap

A steel deck fitting normally used as an attachment for cargo tie down lines.

Deck stringer

The strip of deck plating that runs along the outer adge of a deck.


Inclination of shipways to provide for launching.

Deconsolidation point

Place where cargo is ungrouped for delivery.

Deep floor

A term applied to any of the floors in the forward or after end of a vessel. Due to the converging sides of ships in the bow and stern, the floors become much deeper than in the main body.

Deep frame

A web frame or a frame whose athwartship dimension is over the general amount.

Deep tank

Tank (usually for fuel) having significant depth (typically spanning more than 1 deck interval).

Deep tanks

These usually consist of ordinary hold compartments, but strengthened to carry water ballast. They are placed at either or both ends of the engine and boiler space. They are placed at either or both ends of the engine and boiler space. They are placed st either or both ends of the engine and boiler space. They usaually run from the tank top up to or above the lower deck.




A penalty charge against shippers or consignees for delaying the carrier's equipment beyond the allowed free time. The free time and demurage charges are set forth in the charter party or freight tariff.


A vessel obandoned and drifting aimlessly at sea.


A device consisting of a kingpost, boom with variable topping lift, and necessary rigging for hoisting heavy weights, cargo, etc.






The method of drawing the same lines on a flat surface which have already been drawn on a curved surface. The shapes and lines produced by development are the same as though the curved surface from which they are taken were a flexible sheet which could be spread out flat without change of area or distortion.


Dispatch Half Demurrage on Actual Time Saved Both Ends


Dispatch Half Demurrage on Working Time Saved Both Ends

Diagonal line

A line cutting the body plan diagonally from the frames to the middle line in the loft layout.

Diesel generator

Alternator (generator) directly powered by a diesel prime mover producing AC electrical power. 9kw marine diesel generator

Diesel generator


A position of a flag when lowered part way in salute (method of salute between vessels, like planes dipping wings).




The weight in tons of the water displaced by a ship. This weight is the same as the total weight of the ship when afloat. Displacement may be expressed either in cubic feet or tons, a cubic foot of sea water weighs 64 pounds and one of fresh water weighs 62.5 pounds, consequently one ton is equal to 35 cubic feet of sea water or 35.9 feet of fresh water. The designed displacement of a vessel is her displacement when floating at her designed draft.

Distress signal

A flag display or a sound, light, or radio signal calling for assistance.


A small bag used by seamen for stowing small articles.




Dropping Last Outwards Sea Pilot (Norway)


Decleration of Maritime Labour Convention


Discountless and Non-Returnable Ship and/or Cargo Lost or Not Lost


Diesel Oil


Date of Birth


A basin for the reception of vessels. "Wet" docks are utilized for the loading and unloading of ships.

Docking plan

Detailed structural plan and profile of the lower hull structure required for correct location of the vessel in dry docking.

Docking plan

Docking plan


A hold fast, a short metal rod or bar fashioned to form a clamp or clip and used for holding watertight doors, manholes, or pieces of work in place.

Dog shores

The last supports to be knocked away at the launching of a ship.


The belt on each side of the Equator in which little or no wind ordinarily blows.

Dolly bar

A heavy bar to hold against a rivet, to give backing when riveting.


A cluster of piles driven into the bottom of a waterway and bound firmly together for the mooring of vessels.


Dropping Off Last Sea Pilot (Norway)

Donkey engine

A small gass, stem or electric auxiliary engine, set on the deck and used for lifting, etc.


Dropping Outward Pilot


Department of Transport

Double bottom

A tank whose bottom is formed by the bottom plates of a ship, used to hold water for ballast, for the storage of oil, etc. Also a term applied to the space between the inner and outer bottom skins of a vessel. Also applied to indicate that a ship has a complete inner or extra envelopeof watertight bottom plating. A double bottom is usually fitted in large ships extending from bilge to bilge and nearly the whole length fore-and-aft.

Double bottom

Double skin

Double watertight hull construction, usually referring to hull sides but may include double bottom structure.

Double up

To double a vessel's mooring lines.


A steel plate installed on an existing structural plate and used as a strengthening base for deck fittings or as a repair of a damaged area.



Doubling plates

Extra plates (bars or stiffeners, added to strengthen sections where holes have been cut for hawse pipes, machinery, etc. Also placed where strain or wear is expected.


A pin of wood inserted in the edge or face of two boards or pieces to secure them together.


To take in, or lower a sail. To put out a light. To cover with water.


Dead Reckoning


The distance from the surface of the water to the ship's keel (how deep the ship is into the water).


Depth to which a ship is immersed in water. The depth varies according to the design of the ship and will be greater or lesser depending not only on the weight of the ship and everything on board, but also on the density of the water in which the ship is lying.

DRAFT (DRAUGHT) (of a vessel)

The depth of a vessel below the waterline measured vertically to the lowest part of the hull, propellers or other reference points.

Draft , extreme

Draft measured to the lowest projecting portion of the vessel

Draft marks

Numbers marked on the hull side forward, aft (and amidships on large vessels) indicating the draft.

Draft marks

Draft(or draught)

Depth to which a hull is immersed.

Draft, aft

Draft measured at the stern.

Draft, forward

Draft measured at the bow.

Draft, load

Draft at load displacement.

Draft, marks

The numbers which are placed in a vertical scale at the bow and the stern of a vessel to indicate the draft at each point.

Draft, mean

The average between draft measured at bow and at stern, or for a vessel with a straight keel, the darft measured at the middle length af waterline.


The amount that the aft end of the keel is below the forward end when the ship is afloat with the stern end down.

Drain well

The chamber into which seepage water is collected and pumped by drainage pumps into sea through pump dales.


Vessel designed for the removal of sea bed alluvial sediment. Deepen access channels, provide turning basins for ships, and maintain adequate water depth along waterside facilities.



Dressing ship

A display of national colors at all mastheads and the array of signal flags from bow to stern over the masthead (for special occasions and holidays).

Drift angle

The angle between a ship's head and the direction in which it is moving.

Drift pin

A conical-shaped pin gradually tapered from blunt point to a diameter a little larger than the rivet holes in which it is to be used. The point is inserted in rivet holes that are not fair, and the other end is hammered until the holes are forced into line.

Drill ship

Vessel designed for sea bed drilling operations.

Drill ship

Drill ship

Drip pan

An open container, located on deck under the ends of a pipeline header to retain cargo drippage.



Drop strake

A strake discontinued near the bow or stern.

Dry bulk

Cargo shipped in a dry state and in bulk; e.g., grain, cement.

Dry bulk

Dry bulk

Dry dock

(1) Large basin with sealing caisson for the repair and maintenance of vessels. (2) General term for basin dry docks, floating docks or lift platforms for the maintenance and repair of vessels.

Dry dock

Dry dock

Dry docks

A dock into which a vessel is flated, the water than being removed to allow for the construction or repair of ships.


Dangerous Goods, Solid Cargoes and Containers


Vertical or horizontal large cross-section conduit through which piping, cabling, or fluids may be conducted.

Duct keel

Longitudinal passage within the double bottom, usually on the centreline, extending from the collision bulkhead to the engine room, through which ballast, bilge, fuel and hydraulic piping may be conducted and providing access to double-bottom spaces.


That property of a metal which permits its being drawn out into a thread or wire.

Dumb vessel

A vessel without means of self-propulsion.


Blue working overalls.


Any materials used to block or brace cargo to prevent its motion, chafing, or damage and to facilitate its handling.


Materials of various types, often timber or matting, placed among the cargo for separation, and hence protection from damage, for ventilation and, in the case of certain cargoes, to provide space in which the forks of a lift truck may be inserted.

Duplicating pipe

A piece of tubing, generally brass, used with paint to transfer rivet hole layout from template to plate. The end pf the pipe is dipped in paint, and while still wet is pushed through each template hole, leaving an impression on the plate.


A piece of steel fitted into an opening to cover up poor joints, or the crevices caused by poor workmanship.


Deadweight. Weight of cargo, stores and water, i.e. the difference between lightship and loaded displacement.



Eagle Flies

Pay day


Carefully (watch what you're doing).


Electronic Range Line


East Coast


Electronic Chart Display & Information System


European Community Shipowners Association

EDI - Electronic data interchange

Transmission of transactional data between computer systems.


Electronic Data Interchange for Administration, Commerce, and Trade. International data interchange standards sponsored by United Nations.


Energy Efficient Design Index


Eastern European Terminal Forum


Exclusive Economic Zone


Emergency Head Quarters


Even if Used


A pole or terminal in an electrical circuit. See Polarity.


Term given to hydraulic actuation systems where the hydraulic pressure is produced by electrically driven pumps and controlled via solenoids.


Electric Ventilation


Effective Mooring Revision


Environmental Management System


European Maritime Safety Authority


Electronic Navigational Chart

End seizing

A round seizing at the end of a rope.


Reversing the position of an object or line.


Maximum time period (indicated in hours or days) that a vessel can operate unreplenished while performing its intended role.

Engine control room

Space adjacent to engine room from where engine room systems may be controlled and monitored.

Engine control room

Engine room

Space where the main engines of a ship are located.

Engine room


Electronic Notice of Arrival


(1) The national flag. (2) A junior officer.


The forward under-water portion of a vessel at and near the bow.


Engine Operating Station


Environmental Protection Agency


Estimated Position


Emergency Position Indicating Radio Beacon. EPIRB is a small hand-held battery-operated transmitter, actuated by water, for use in locating vessels in distress. EPIRBs are devices that trasmit a digital signal on the international distress signal frequency 406 MHz. Designed to work with satellites, EPIRBs are detectable by COSPAS-SARSAT satellites, which orbit the poles, and by the GEOSAR system which consists of GOES weather satellites and other geostationary satellites. There are two types of EPIRBs, Category I or Category II. Category I EPIRBs float-free and are automatically activated by immersion in water, and they are detectable by satellite anywhere in the world. Category II EPIRBs are similar to Category I, except in most cases they are manually activated, however some models can be automatically activated.



Emergency Position Indicating Radio Beacons


The process of hoisting into place and joining the various parts of a ship's hull, machinery, etc.


Evaluation of Safety and Pollution Hazards


Estimated Time of Arrival


Estimated Time of Completion


Estimated Time of Departure


Emergency Towing-off Pennant System


Environmental Tags System


Estimated Time of Sailing

Even keel

When a boat redes on an even keel, its plane of flotation is either coincident or parallel to the designed water line.


Enhanced Vessel Traffic Management System


Executive Committee

Expansion joint

A term applied to a joint which permits linear movement to take up the expansion and contraction due to changes in temperature.

Expansion trunk

A raised enclosure around an opening in the top of a liquid cargo tank which allows for heat expansion of the cargo.

Expansion trunks

Trunkways extending a short way into oil tanker compartments from the hatches. When the compartment is filled, the trunk is partly filled, and thus cuts down the free surface of the cargo, improving stability. Free space at the top is left for any expansion of the oil.


Ex Works


The forward end of the spacs below the upper decks of a ship which lies next abaft the stem, where the sides approach very near to each other. The hawse pipes are usually run down through the eyes of a ship.

Eye bolt

A bolt having either a head looped to form a worked eye, or a solid head with a hole drilled through it forming a shackle eye. Its use is similar to that of a pad eye.

Eye plate

Fitting used for mooring arrangements.

Eye plate




To shape, assemble and secure in place the component parts in order to form a complete job.

Face plate

A narrow stiffening plate welded alone the edge of any web frame or stiffener.

Factory ship

High endurance vessels designed for processing and packing whale or fish resources off-loaded by smaller whaling or fishing vessels.


To fair a line means to even out curves, sheer lines, deck lines etc., in drawing and mold loft work.

Fairing or Fairing up

Correcting or fairing up a ship's lines or structural members; assembling the parts of ship so that they will be fair, that is, without kinks, bumps, or waves.


A device consisting of pulleys or rollers arranged to permit the reeling in of a cable from any direction; often used in conjunction with winches and similar apparatus.



Plating fitted, in the shape of a frustrum of a cone, around the ends of shaft tubes and struts to prevent an abrupt change in the stream lines. Also any casting or plate fitted to the hull for the purpose of preserving a smooth flow of water.


A single turn of rope when a rope is coiled down.

Fake down

To fake line back and forth on deck.


Facilitation Committee


Commonly the antire length of rope used in a tackle, though strictly it means only the end to which the power is applied.


The overhanging stern section of a vessel, from the stern post aft.


Free Alongside Ship. Seller delivers goods to appropriate dock or terminal at port of embarkation and buyer covers costs and risks of loading.


Six feet. A sea-going measure of length.


To unite closely two planks or plates, so as to bring the surfaces into nitimate contact.

Faying surface

The contact surface between two adjoining parts.


Free of Dispatch


Freight Demurrage Deadfreight


Free Discharge

Feeder service

Transport service whereby loaded or empty containers in a regional are transferred to a "mother ship" for a long-haul ocean voyage.


Pieces of wood which from the rim of a wheel.

Fend off

To push off when making a landing.


This term is applied to various devices fastened to or hung over the sides of a vessel for the purpose of preventing rubbing or chafting. On small craft, such as tug boats, it consists of a timber or steel structure running fore and aft along the outside of the vessel above the water line. On the wearing surface. a strip of iron bark or a piece of flat bar iron is attached.



Vessel used to convey passengers and/or vehicles on a regular schedule between 2 or more points.


Forty foot container equivalency unit Standard 40′ Container


Fridays/Holidays Excluded


Fridays/Holidays Included


A tapered wooden pin used to separate the strands when splicing heavy rope.


Framework built around a deck hatch ladder, leading below.

Fidley deck

A partially raised deck over the engine and boiler rooms, usually around the smokestack.

Field day

A day for general ship cleaning.


The bust, often of a woman, on the bow of a vessel, just under the bowscript.


The rounded edge of a rolled steel angle or bar.


Free In/Liner Out. Seafreight with which the shipper pays load costs and the carrier pays for discharge costs.


A projecting keel.


Free In/Out. Freight booked FIO includes the sea freight, but no loading/discharging costs, i.e. the charterer pays for cost of loading and discharging cargo.


Free In/Out Stowed. As per FIO, but includes stowage costs.


Free In/Out Stowed, Lashed, Secured and Dunnaged. As per FIO, but includes cost of lashing securing and dunnaging cargo to Masters satisfaction.


Free In/Out and Trimmed. Charterer pays for cost of loading/discharging cargo, including stowage and trimming.


Free In/Out and Trimmed. As per FIOS but includes trimming the leveling of bulk cargoes

Fish plate

A triangular-shaped steel plate used to strengthen the connection between the towing bridle and the towing hawser.

Fish plate


Free In Trimmed


Free In Wagon

Fixed costs

Costs that do not vary with the level of activity. Some fixed costs continue even if no cargo is carried; for example, terminal bases, rent, and property taxes.


Chartering a Vessel

Flag State

The nation in which a vessel is registered and which holds legal jurisdiction as regards operation of the vessel, at home or abroad.


Flag pole, usually at the stern of a ship, carries the ensign.

Flame screen

A corrosion-resistant fine wire mesh screen used to cover certain openings on tank vessels to prevent the passage of flame into the tank.


The turned edge of a shape or girder, which acts to resist bending strain.


Outward curvature or widening of the hull above the waterline present in the bow section (of a conventional bow) to avoid shipping water.


The spreading out from the central vertical plane of the body of a ship with increasing rapidity as the section rises from the waterline to the rail.

Flared bow

A bow with an extreme flare at the upper and forcastle deck.


A small partial deck, built level, without curvature.

Flemish down

To coil flat down on deck, each fake outside the other, beginning in the middle and all close together.

Floating drydock

A U-shaped dock with double skins which is filled by opening up the sillcocks, and allowed to settle sothe middle section will be lower than the keel of the ship so that repairs can be made on her hull.

Floodable length

The length of the hull, at any point, that can fl ood without immersing the margin line. Important in studying the safety of ships.


Vertical transverse full-breadth plating between inner bottom and bottom shell plating.

Floor plan

A horizontal section, showing the ship as divided at a water or deck line.


Vertical flat plates running transverse of the vessel, connecting the vertical keel with the margin plates or the frames to which the tank top and bottom shell is fast-ened.


The parts of a wrecked ship and goods lost in shipwreck, both found floating.


Full Liner Terms Shipowner pays to load and discharge the cargo


The palm of an anchor. The broad holding portion which penetrates the ground.

Flush deck

A deck running from stem without being broken by forecastle or poop.

Flush deck hatch

Hatch in a deck with no coaming.

Flush deck ship

Vessel having an upper deck extend continuously from bow to stern.


A substance such us as borax, used in welding to help in the melting of the metal. Flux also serves to stabilize the electric arc, steady the flow of the filler metal into the weld and protect the weld from oxidation.


Federal Maritime Commission US government agency


Fathoms 6 feet


Fuel Oil/Intermediate FO


Free on Board. Seller sees the goods "over the ship's rail" on to the ship which is arranged and paid for by the buyer


A modem version of the old term "forecastle," or bow section of the ship, where the crew lived.

Fodley hatch

Hatch around smokestack and uptake.


Firm Offer


For Our Guidance

Fog horn

A sound signal device (not necessarily mechanically operated).


Said of a vessel when forced to heave to or lie at anchor due to fog.


Free On Quay


Free On Rail

Force majeure

The tittle of a common clause in contracts, exempting the parties from nonfulfillment of their obligations as a result of conditions beyond their control, such as earthquakes, floods, or war.


Clause limiting responsibilities of the charterers, shippers and receivers due to events beyond their control.

Fore and aft

Parallel to the ship's centerline.

Fore peak

The narrow extremity of a vessel's bow. Also the hold space within it.

Fore peak tank

Tank (often for ballast/trimming) forward of the collision bulkhead.

Fore peak tank

Fore peak tank

Fore rake

The forward part of the bow which overhangs the keel.

Fore, forward

Toward the stem. Between the stem and amidships.


That part of a hull forward of amidships.


Raised and enclosed forward superstructure section of the hull.



A short structure at the forward end of a vessel formed by carrying up the ship's shell plating a deck height above the level of her uppermost complete deck and fitting a deck over the length of this structure.

Forecastle deck

A deck over the main deck at the bow.


Foremost section of exposed main deck.


The forward end of a vessel's stem which is stepped on the keel.


Or breast hook.

Forepeak bulkhead

The bulkhead nearest the stem, which forms the after boundary of the forepeak tank. When this bulkhead is extended from the bottom of the ship to the weather deck, it is also called the collision bulkhead.

Forest product carrier

Vessel designed for the transportation of processed timber with large hatchways simplifying stowage and transfer of cargo.

Forest product carrier


A mass of metal worked to a special shape by hammering, bending, or pressing while hot.

Fork beam

A half beam to support a deck where hatchways occur.

Formal safety assessment (FSA)

A process for assessing the safety of a ship by studying the risks, their likelihood and consequences.

Forty-foot equivalent unit (FEU)

Unit of measurement equivalent to one forty-foot container. Two twenty foot containers (TEUs) equal on FEU.


Towards or at the fore end of a vessel. (Abbr. Fwd or For'd.)

Forward perpendicular

A line perpendicular to the keel line, and intersecting the forward side of the stem at the designed load water line.


Free On Truck


Jammed, not clear.

Fouled hawse

Said of the anchor chain when moored and the chain does not lead clear of another chain.


To fit and bed firmly. Also, equipped.


To sink (out of control).

FOW (1)

First Open Water

FOW (2)

Free On Wharf


Fall Preventing Device


Floating production, storage and offloading vessel.



Vertical structural component supporting and/or stiffening hull side plating and maintaining the transverse form.


Frame head

The section of a frame that rises above the deck line.

Frame lines

Lines of a vessel as laid out on the mold loft floor, showing the form and popsition of the grames. Also the line of intersection of shell with heel of frame.

Frame spacing

The fore-and-aft distances between frames, heel to heel.

Frame station(s)

Points at which transverse frames (or floors) are located, indicated on the baseline, numbered from zero at the aft perpendicular and terminating at or beyond the forward perpendicular. Stations abaft the aft perpendicular are numbered negatively.


The ribs of a ship.


Fast Rescue Craft


Free of discharge costs to Owners


Vertical measurement from the vessel's side amidships from the load waterline to the upperside of the freeboard deck.



Freeboard deck

The uppermost complete deck exposed to weather and sea, which has permanent means of weathertight closing of all openings in the exposed part, and below which all openings in the vessel's sides are fitted with permanent means of watertight closing.

Freefall lifeboat

Some ships have freefall lifeboats, stored on a downward sloping slipway, dropping into the water as holdback is released. Such lifeboats are considerably heavier to survive the impact with water. Freefall lifeboats are used for their capability to launch nearly instantly and high reliability, and since 2006 are required on bulk carriers that are in danger of sinking too rapidly for conventional lifeboats to be released. Tankers are required to carry fireproof lifeboats, tested to survive a flaming oil or petroleum product spill from the tanker. Fire protection of such boats is provided by insulation and sprinkler system, which has pipe system on top, through which water is pumped and sprayed to cool the surface. This system, while prone to engine failure, allows fireproof lifeboats to be built of fiberglass and not only metal.

Freeing port

A large opening in the bulwark on an exposed deck of a seagoing vessel which provides for the rapid draining of water from that deck.

Freeing port

Freeing ports

Heles in the bulwark or rail, which allow deck wash to drain off into the sea. Some freeing ports have swing gates which allow water to drain off but which aytomatically close from sea water pressure.

Freight, demurrage, and defence

Class of insurance provided by a protection and indemnity (P&I) club that covers legal costs incurred by a shipowner in connection with claims arising from the operation of the ship.


A ship designed to carry all types of general cargo, or "dry cargo."


Free Surface Effect


Floating Systems Group


Flag State Implementation


Fire Safety Systems


Floating Storage Unit


External fairing through which exhaust ducting is conducted.



Strips of timber or boards fastened to frames, joists, etc., in order to bring their faces to the required shape or level, for attachment of sheating, ceiling, flooring etc.


Fresh Water Arrival Draft


Fresh Water Departure Draft


For Your Guidance


For Your Information




Anything of Government Issue.


General Average


A slang term applied to various fittings.


A standard of measure.


Kitchen compartment aboard a vessel.


The process of coating one metal with another, ordinarily applied to the coating or iron or steel with zinc. The chief purpose of galvanizing is to prevent corrosion.

Gang board

Same as gang plank.

Gang plank

A board with cleats forming a bridge reaching from a gengway of a vessel to the wharf.


The opening in the bulkwarks of a vessel through which persons come on board of disembark. Also a gang plank.


A line rove through a single block secured aloft.


High level structure supporting a traversing lifting appliance.


Garboard strake

Strake (line) of shell plating immediately adjacent to the keel (centreline) plating.

Garboard strake

A strake which ends before reaching the stem or stern post. Such strakes are laid at or near the middle of the ship's sides to lessen the spiling of the plating.

Gas carrier

Tanker designed for the transportation of liquefied gases.

Gas carrier

Gas free

The process of removing all hazardous gases and residues from the compartments of a vessel


An elastic packing material used for making joints watertight.


Packing materials, by which air, water, oil, or steam tightness is secured in such places as on doors, hatches, steam cylinders, manhole covers, or in valves, between the flanges of pipes, etc. Such materials as rubber, canvas, asbestos, paper, sheet lead and copper, soft iron, and commercial products are extensively used.


A point at which freight moving from one territory to another is interchanged between trasportation lines.

Gather way

To attain headway (to get going or pick up speed).


A waterway marker which measures the level of the water in foot increments; also refers to the specific measure on the gauge.


Goal Based Standard


The general name for ropes, blocks and tackles, tools, etc. (things).

General arrangement

Highly detailed plan drawings of the general layout of a vessel.

General arrangement


Green House Gas


A metal fitting that holds a member in place, or presses two members together.

Gilguy (or gadget)

A term used to designate an object for which the correct name has been forgotten.

Gipsey (gypsey)

A drum of a windlass for heaving in line.


(1) Longitudinal continuous member with a vertical web providing support of deck beams. (2) Longitudinal continuous vertical plating on the bottom of single- or double-bottomed vessels.


The distance measured on any frame line, from the intersection of the upper deck with the side, around the body of the vessel to corresponding point on the opposite side. The half gith is taken from the center line of the keel to the upper deck beam end.


Global Integrated Shipping Information System


Term used by mariners for a barometer.

Glory hole

Steward's quarters.




Global Maritime Distress Safety System. The GMDSS is an internationally agreed-upon set of safety procedures, types of equipment, and communication protocols used to increase safety and make it easier to rescue distressed ships, boats and aircraft. GMDSS consists of several systems, some of which are new, but many of which have been in operation for many years. The system is intended to perform the following functions: alerting (including position determination of the unit in distress), search and rescue coordination, locating (homing), maritime safety information broadcasts, general communications, and bridge-to-bridge communications. Specific radio carriage requirements depend upon the ship's area of operation, rather than its tonnage. The system also provides redundant means of distress alerting, and emergency sources of power.



Guide to Manufacturing & Purchasing Hoses for Offshore Moorings

GN (or GR)

Grain (capacity)


Gencon a standard bimco charter party form


Global Navigation Satellite Systems


Gas Oil

Go adrift

Break loose.

Golden Slippers

Tan work shoes issued to U.S. Maritime Service trainees


A return, or 180o bend, having one leg shorterthan the other. An iron swivel making up the fastening between a boom and a mast. It consists of a pintle and an eyebolt, or clamp.


Atool with an half round cutting edge used to cut grooves.


General Purposes Committee


A small anchor with several arms used for dragging purposes.


A wooden lattice-work covering a hatch or the bottom boards of a boat; similarly designed gratings of metal are frequently found on shipboard.


An open iron lattice work used for covering hatchways and platforms.

Graveyard watch

The middle watch.

Graving docks

A dry dock. The vessel is floated in, and gates at the entrance closed when the tide is at ebb. The remaining water isthen pumped out, and the vessel's bottom is graved, or cleaned.



Green sea

A large body of water taken aboard (ship a sea).


Metal protective bars of sea chests and propeller thrusters.


The sharp forward end of the dished keel on which the stem is fixed.


A reing of fiber usually soaked in red lead or some other packing material, and used under the heads of bolts and nuts to preserve tightness.

Gross registered tonnage

A formula-derived measure of the internal (enclosed) volume of a vessel less certain excluded spaces. (Stated in volumetric tons where 1 ton = 100 ft3 , 2.8317 m3.) (Abbr. grt.)

Gross tons

The volume measurement of the internal voids of a vessel wherein 100 cu. ft. equals one ton.

Ground tackle

A term used to cover all of the anchor gear.


Running ashore (hitting the bottom).


Large pieces of timber laid across the ways on which the keel blocks are placed. Also the large blocks and plans which support the cradle on which a ship is launched.


The grouping together of several compatible consignments into a full container load. Also referred to as consolidation.


Glass Reinforced Plastic


Gross Registered Tonnage


Good Safe Berth


Good Safe Port




A metallic eye bolted to the stern post, on which the rubber is hung.


The upper edge of a vessel or boat's side.

Gunwale (gunnel)

That part of a barge or boat where the main deck and the side meet.

Gunwale bar

A term applied to the bar connecting a stringer plate on a weather deck to the sheer strake.


A steel plate used for reinforcing or bracing the junction of other steel members.


Gusset plate

A tie plate, used for fastening posts, frames, beams, etc., to other objects.

Gutter ledge

A bar laid across a hatchway to support the hatches.


The sunken trough on the shelter deck outer edge which disposes of the water from the deck wash.


Wire or hemp rope or chains to support nooms, davits, ets., laterally. Guys are employed in pairs. Where a span is fitted between two booms, for example, one pair only is required for the two.


The distance from the centre of gravity to the line of action of the buoyancy force. It is a measure of a ship's ability to resist heeling moments.






Hose Ancillary Equipment & Managing Hoses in the Field


To address a vessel, to come from, as to hail from some port (call).

Half deck

A short deck below the main deck.

Half model

A modle of one side of a ship, on which the plate lines are drawn in.

Half-breadth plan

A plan or top view of half of a ship divided longitudinally. It shows the water lines, bow and buttock lines, and diagonal lines of construction.


The position of a flag when lowered halfway down.

Halliards or halyards

Ropes used for hoisting gaffs and sails, and signal flags.


A member of the ship's company.

Hand lead

A lead of from 7 to 14 pounds used with the hand lead line for ascertaining the depth of water in entering or leaving a harbor. (Line marked to 20 fathoms.)

Hand rail

A steadying rail of a ladder (banister).

Hand rope

Same as "grab rope" (rope).

Hand taut

As tight as can be pulled by hand.


Term used in contracts, meaning the process of providing exclusive, unencumbered, peaceful, and vacant possession of and access to a concession area and the existing operational port infrastructure and also all rights, title and interest in all the movable assets and all the facilities by the government or the port authority on the hand over date for the conduct of terminal operations.


A watch tackle (small, handy block and tackle for general use).


Dry bulk carrier of 35 - 50,000 tonnes deadweight, popular for full efficiency, flexibility and low draft (<12 m).


A term applied to bulk carriers of 40 000-65 000 DWT.

Hang from the yards

Dangle a man from one of the yard arms, sometimes by the neck, if the man was to be killed, and sometimes by the toes, if he was merely to be tortured. A severe punishment used aboard sailing ships long ago. Today, a reprimand.

Hard patch

A plate riveted over another plate to cover a hole or break.


The fore parts of the wales of a vessel which compass her bows and are fastened to the stem, thickened to withstand plunging.


Opening in a deck providing access for cargo, personnel, stores, etc.


Hatch bars

The bars by which the hatches are fastened down.

Hatch coaming

Raised rim of vertical plating around a hatchway to prevent entrance of water, the upper edge of which forms a sealing surface with the hatch-lid or cover.

Hatch coaming


One of the large square openings in the deck of a ship through which freight is hoisted in or out, and access is had to the hold. There are four pieces in the frame of a hatchway. The fore-and-aft pieces are called coaming and those athwartship are called head ledges. The head ledges rest on the beams and the carlines extending between the beams. There may be forward, main and after hatcheays, according to the size and character of the vessel.


The part of a ship's bow in which are the hawse holes for the anchor chains.

Hawse buckler

An iron plate covering a hawse hole.

Hawse hole

A hole in the boow through which a cable or chain passes. It is a cast steel tube, having rounded projecting lipe both inside and out.

Hawse pipe

Steel pipe duct through which the anchor cable is led overboard.

Hawse pipe

Hawse plug or block

A stopper used to prevent water from entering the hawse hole in heavy weather.


A pipe lead-in for anchor chain through ship's bow.


A large circumference rope used for towing or mooring a vessel or for securing it at a dock.




Left-handed rope of nine strands, in the form of three three-stranded, right-handed ropes.


Hydro Chloro Fluoro Carbons


Half Dispatch Working Time Saved


(1) The bow of a vessel. (2) Term given to toilet facilities usually in the smaller craft context.

Head ledges

See Hatchway

Head of navigation

The uppermost limit of navigation from the mouth of a waterway.

Head room

The height of the decks, below decks.


The reinforced, vertical plate which connects the bow rake bottom to the rake deck of a barge or square-stemmed boat.


The inside center strand of rope.


The vertical movement of a ship, as a rigid body, in a seaway.


Heave around

To revolve the drum of a capstan, winch or windlass. (Pulling with mechanical deck heaving gear).

Heave away

An order to haul away or to heave around a capstan (pull).

Heave in

To haul in.

Heave short

To heave in until the vessel is riding nearly over her anchor.

Heave taut

To haul in until the line has a strain upon it.

Heave the lead

The operation of taking a sounding with the hand lead (to find bottom).

Heave to

To bring vessel on a course on which she rides easily and hold her there by the use of the ship's engines (holding a position).

Heaving line

A small line thrown to an approaching vessel, or a dock as a messenger.

Heavy-lift vessel

Vessel designed specifically for the loading/discharge and transportation of very heavy cargoes.

Heavy-lift vessel

Heavy-lift vessel


Inclination of a vessel to one side. [Alt list.]




Vertical distance between any two decks, or vertical distance measured from the base line to any water line.


A term applied to the tiller, wheel, or steering gear, and also the rubber.

Helm port

The hole in the counter of a vessel through which the rubber stock passes.


Rope made of the fibers of the hemp plant and used for small stuff or less than 24 thread (1.75 inch circumference). (Rope is measured by circumference, wire by diameter.)


Mercury Working Group

High, wide and handsome

Sailing ship with a favorable wind, sailing dry and easily. A person riding the crest of good fortune

Hip towing (hipping)

A method of towing whereby the vessel being towed is secured along-side the towboat



Heavy Metal Scrap


Hazardous and Noxious Substances




A scrub-broom for scraping a ship's bottom under water.

Hog frame

A fore-and-aft frame, forming a truss for the main frames of a vessel, to prevent bending.

Hog sheer

The curve of the deck on a vessel constructed so that the middle is higher than the ends.


A ship that is damaged or strained so that the bottom curves upward in the middle opposite of sagged.


A ship is said to hog when the hull is bent concave downwards by the forces acting on it. Hogging is the opposite of sagging.


Hoist away

An order to haul up.


That part of a ship where cargo or supplies are carried.

Hold beams

The beams that support the lower deck in a cargo vessel.

Hold fast

A dog or brace to hold objects rigidly in place.


An imperfection, spots left unfinished in cleaning or painting.

Holy stone

The soft sandstone block sailors use to scrub the deck, so-called, because seamen were on their knees to use it.


A covering for a companion hatch, scuttle or skylight.


The endmost plate of a complete strake. The hooding-ends fit into the stem or stern post.

Hopper barge

Barge designed with a single hopper type hold for the transport of bulk cargo and where the cargo is discharged (dumped) through the bottom of the vessel.

hopper barge

Hopper tank

Lower side ballast tank in a bulk carrier, shaped and positioned to create a hopper form to the cargo hold.

Hopper tank

Horn cleat

A fitting, usually with two horn-shaped ends, to which lines are made fast. The classic cleat is almost anvil-shaped.

Horn cleat

Horn cleat


Setting the frames of a vessel square to the keel after the proper inclination to the vertical due to the declivity of the keel has been given.

Horse latitudes

The latitudes on the outer margins of the trades where the prevailing winds are light and variable.


A standard unit of power which is often classified in connection with engines as brake, continuous input, intermittent, output, or shaft horsepower.

Horseshoe plate

A small, light plate fitted on the counter around the rubber stock for the purpose of preventing water from backing up into the rudder trunk. Frequently it is made in two pieces.


That portion of a mast between the deck and the hounds.


The mast head projections which support the trestle trees and top. Also applied in vessels without trestle trees to that portion at which the hound band for attaching the shrouds is fitted.


To stow or secure in a safe place. A top-mast is housed by lowering it and securing it to a lowermast.

House flag

Distinguishing flag of a merchant marine company flown from the mainmast of merchant ships.


That portion of a mast below the surface of the upper deck.


Vessel designed to ride on a cushion of air formed by downthrusting fans.



Horse Power


Hydrostatic Release Unit


Harmonised System of Survey and Certification


To keep close.


A worn out vessel.


The main body or primary part providing global strength, buoyancy and hydrodynamic qualities of a vessel.


Hull down

Said of a vessel when, due to its distance on the horizon, only the masts are visible.

Hull girder

Combined hull structure contributing to the longitudinal global strength of a hull treated as analogous to a girder.


Force of wind over 65 knots.

Hurricane deck

Same as bridge.


High Water


Hot Work Permit


High-speed craft with immersed foils for developing hydrodynamic lift at speed and a consequential reduction in resistance.



Hydrographic vessel

Vessel designed for the survey of seabed topography, currents, etc., relevant to marine navigation.


Rotatable lateral fin providing vertical directional control for submersible craft.

Hydrostatic test

A pressure test employing a static head of water applied to various compartments or components of a vessel.




International Air Pollution Prevention


International Association of Clasification Societies


International Association of Drilling Contractors


International Aeronautical and Maritime Search and Rescue Manual


International Association of Ports and Harbors


International Air Transport Association


Intermediate Bulk Container


A structural shape with cross section resembling the letter I.


Integrated Bilge Treatment System

Ice breaker

Vessel designed for transiting sea ice or for the purpose of creating a channel in polar or winter ice for the passage of other vessels.

Ice breaker


Caught in the ice.


International Chamber of Shipping


International Committee on Seafarers' Welfare


A term applied to several piles that are bound together situated either at the corner of a pier or out in the stream and used for docking and warping vessels.


International Energy Agency


Intermediate Fuel Oil


International Federation of Shipmaster's Association


International Hydro graphic Organization


International Ice Patrol


Industry Lifeboat Group


International Maritime Bureau


International Maritime Dangerous Goods Code


International Maritime Health Association


International Maritime Organisation


IMO Search & Rescue manual


International Marine Purchasing Association


International Maritime Solid Bulk Cargo Code


Towards the center line of a ship (towards the center).

Inboard profile

A plan representing a longitudinal section through the center of the vessel, showing heights of decks, location of transverse bulkheads, assignment of various spaces and all machinery, etc., located on the center or betweenthe center and the shell on the port side.




Placing a port on a vessel's itinerary because the volume of cargo offered by that port justifies the cost of routing the vessel.

Inert Gas

A gas such as carbon dioxide or nitrogen that is used to make an oxygen deficient atmosphere. Inerted tanks are useful for preserving cargo integrity and reducing the explosive potential of cargo tanks.


Implies that a tank is filled with an inert gas.


Irradiated Nuclear Fuel


A measurement of liquid cargo in a tank. It is the distance from the top of the cargo to the bottom of the tank. It is the opposite of ullage.

Inner bottom

The tank top.

Inner Shell

A plated surface or "shell" inside the outer shell plating, used as additional protection in case of collision or other accidents. The space between the inner and outer shells is often used as a storage space for liquid ballast or cargo.

Inserted packing red lead

Soaked canvas strip placed between connections that cannot be caulked successfully; stop waters.

Integrated tow

A tow of box-ended barges which, as a complete unit, is raked at the bow, boxed at the intermediate connections, and boxed or raked at the stern.


Plates which fit between floors to stiffen the double bottom of a ship. Intercostal comes from the Latin words inter, meaning between, and costa, meaning rib.


Movement of cargo containers interchangeably between trasport modes where the equipment is compatible within the multiple systems.


Carriage of a commodity by different modes of transport, i.e. sea, road, rail and air within a single journey.


International Oil Pollution Compensation


International Petroleum Industry Environmental Conservation Association

Irish pennant

An untidy loose end of a rope (or rags).


International Recommended Transit Corridor


Indigenous Shipowners Association of Nigeria


International Ship Security Certificate


International Oil Tanker & Terminal Safety Code

Isherwood system

A method of framing a vessel which employs closely spaced longitudinals, with extra heavy floors spaced further apart.


International Stability Operations Association


International Sewage Pollution Prevention Certificate


Intertanko Technical Committee


Intersessional Working Group on Maritime Security


International Tonnage Certificate


International Transport Federation


International Tanker Owners Pollution Federation


If Used


If Used, Actual Time Used To Count


If Used, Half Actual Time Used To Count


Institute Warranty Limits




The flag similar to the union of the national flag.

Jack ladder

A ladder with wooden steps and side rops

Jack Tar

Sailors were once called by their first names only, and Jack was their generic name. Tar came from seamen's custom of waterproofing clothing using tar.


Flagpole at the bow of a ship.

Jacob's ladder

A ladder of rope with rungs, used over the side.


To wedge tight.


Items that are thrown overboard from a vessel in distress. Discarded cargo that washes ashore.


To throw goods overboard.


A landing wharf or pier; a dike at a river s mouth.

Jews harp

The ring bolted to the upper end of the shank of an anchor and to which the bending shackle secures.


The arm or boom of a crane providing the reach (working radius).



The lap a joint by keeping one edge straight and bending the other, in order to leave both surface even on one side.

Jolly Roger

A pirate's flag carrying the skull and cross-bones.


That portion of a shaft or other revolving member shich transmits weight directly to end is in immediate contact with the bearing in which it turns.

Jumbo derrick

A derrick designed with a very high lifting capacity, often installed on heavy-lift vessels.


The conversion of a vessel to increase displacement by means of a mid-length transverse cut and the installation of a new section.

Jump ship

To leave a ship without authority (deserting).


A term applied to temporary structures, such as masts, rubbers, etc., used in an emergency.

Jury rig

Makeshift rig (emergency rig).




The lowest structural member of a ship or boat which runs the length of the vessel at the centerline and to which the frames are attached.

Keel (plate)

Lowest longitudinal strake of plating along the bottom centreline of the hull.

Keel (plate)

Keel block(s)

Support block(s) located beneath the keel strake which are employed during dry-docking of a vessel.

Keel blocks

Blocks on which the keel of a vessel rests when being built, or when she is in a drydock.

Keel bracket

A bracket, usually a triangular plate, connecting the vertical keel and flat keel plates, between the frames or floors of a ship.

Keel docking

In dry docking, the weight of a ship is carried almost entirely on the keelson provide the means of distributing the pressure on the center line and docking keels composed of doubling strips of plate or built-up girders are sometimes fitted on the bottom at a distance from the center line corresponding to the best position for the bilge block. The docking keels are fitted in a fore-and-sft direction, generally parallel or nearly so to the keel.

Keel line

An imaginary line describing the lowest portion of a vessel's hull.

Keel rider

A plate running along the top of the floors and connecting to the vertical keel.


To tie a rope about a man and, after passing the rope under the ship and bringing it up on deck on the opposite side, haul away, dragging the man down and around the keel of the vessel. As the bottom of the ship was always covered with sharp barnacles, this was a severe punishment used aboard sailing ships long ago. Today, a reprimand.


Longitudinal vertical member above the keel to which frames are attached. (Wooden construction.)

Keep a sharp look-out

A look-out is stationed in a position to watch for danger ahead. To be on guard against sudden opposition or danger.

Kenter shackle

A detachable shackle which is used to join two forged anchor chain links together.

Kenter shackle


Pig iron used either as temporary weight for inclining a vessel or as permanent ballast.


In joiner work, a slit or cut made by a saw. Kerfs are made where timber joints require adjusting. Also applied to the channel burned out by a cutting torch.

Kevel (caval)

A heavy, metal deck fitting having two horn-shaped arms projecting outward around which lines may be made fast for towing or mooring of a vessel hull.


King posts

The main center pillar posts of the ship. May be used as synonym for samson post.


The upper spoke of a steering wheel when the rudder is amidships, usually marked in some fashion (top spoke of neutral steering wheel).


A twist in a rope.


Outdated term for a bracket connecting a deck beam and side frame.

Knock off

To stop, especially to stop work.

Knocked down

The situation of a vessel when listed over by the wind to such an extent that she does not recover.


One nautical mile per hour (1.852 km/h, 0.5144 m/s).

Knot (rope)

A twisting, turning, tying, knitting, or entangling of ropes or parts of a rope so as to join two ropes together or make a finished end on a rope, for certain purpose.


Abrupt change in direction of hull surface or structure.

Knuckle line

A line on the stern of a ship, on the cant frames, which divides the upper and lower parts of the stern.!

Knuckle plate

A plate bent to form a knuckle.

Kort nozzles

A steel tube that surrounds a propeller, directing the water and improving efficiency.Kort nozzles are engineered to improve the flow around the propellers. They are similar in some ways to an airplane propeller.


Key Performance Indicator




A vessel is said to labor when she works heavily in a seaway (pounding, panting, hogging and sagging).


A metal, wooden or rope stairway.

Lame duck

Term for disabled vessel that had to fall out of a convoy and thus became easy prey for submarines.


The spaced distance from the edge of a bar or plate to the center of the rivet holes.

Landing craft

Flat-bottomed shallow-draft vessel designed to beach, with a bow and/or stern ramp for the transfer of cargo/payload.

Landing edge

Opposite of sight edge, which see.

Landing ship dock

Large naval vessel capable of carrying small landing craft and amphibious vehicles, despatched via a floodable stern dock within the hull.

Landing strake

The second strake from the gunwale.


The seaman's term for one who does not go to sea.


A method of measuring the space capacity of Ro/Ro ships whereby each unit of space (Linear Meter) is represented by an area of deck 1.0 meter in length x 2.0 meters in width.


A rope made fast to an article for securing it (knife lanyard, bucket lanyard, etc.), or for setting up rigging.


A term applied to the distance that one pieces is laid over the other in making a lap joint.


Applied to boats built on the clinker system, in which the starkes overlap each other. The top strake always laps on the outside of the strake underneath.


Abbreviaton for "lighter aboard ship". A specially constructed vessel equipped with an overhead traveling gantry crane for lifting specially designed barges out of water and stowing them into the cellular holds of the vessel as well.

LASH (1)

To hold goods in position by use of Ropes, Wires, Chains or Straps etc.

LASH (2)

Lighter Aboard Ship a vessel that loads small barges direct from the water


A passing and repassing of a rope so as to confine or fasten together two or more objects; usuafly in the form of a bunch.




To place in the water.

Lay aloft

The order to go aloft (go up above).

Laying out

Placing the necessary instructions on plates, shapes, etc., for planing, shearing, punching, bending, flanging, beveling, rolling, etc., from the templates made in the mold loft or taken from the ship.


A low headroom space below decks used for provisions or spare parts, or miscellaneous storage.

Lazy guy

A light rope or trackle by which a boom is prevented from swinging around.


Limiting Danger Line

Lee shore

The land to the leeward of the vessel (wind blows from the ship to the land).


The direction away from the wind.


Legal Committee

Length between perpendiculars

The length of a ship measures from the forward side of stem to the aft side of the stern post at the height of the designed water line.

Length over all

The length of a ship measured from the foremost point of the stem to the aftermost part of the stern.


Permission to be absent from the ship for a short period (authorized absence).


Rigid-hulled survival craft deployed from a parent vessel.



A line secured along the deck to lay hold of in heavy weather; a line thrown on board a wreck by life-saving crew; a knotted line secured to the span between life-boat davits for the use of the crew when hoisting and lowering.

Lift a template

Is to construct a template to the same size and shape as the part of the ship involved. To lay aot a template is to transfer the size and shape into the material and work it into the fabricated object.


Transferring marks and measurements from a drwing, model, etc., to a plate or other object, by templates or other means.

Lifting gear

The lifting equipment (i.e., cranes) for loading and discharging operations.

Light load line

The water line when the ship rides empty.

Light, fixed

A thick glass, usually circular in shape, fitted in a frame fixed in an opening in a ship's side, deck house, or bulkhead to provide access for light. The fixed light is not hinged.

Lightening hole

Large hole cut in a structural member to reduce its weight.

Lightening hole


A full-bodied, heavily built craft, usually not self-propelled, used in bringingmarchandise or cargo alongside or in transferring same from a vessel.


The vessel condition without any form of deadweight aboard (incl.fuel and ballast).

Limber chains

Chains passing through the limber holes of a vessel, by which they may be cleared of dirt.

Limber hole

Small hole or slot cut in a structural member to permit the drainage of liquid.

Limber holes

Holes in the bottoms of floors throught which bilge water runs through tank sections to a seepage basin, where it is then pumped out. The row of holes constitutes the limber passage.

Limber strake

The strake on the inner skin of a vessel which is nearest to the keel.


A general term for light rope.

Line haul

The movement of freight over the tracks of a transportation line from one location (port or city) to another.


Vessel (over 1000 grt) operating on a regular route between ports according to a particular schedule.


The ropes or cables used on a vessel for towing, mooring, or lashing.

Lines plan

Plans indicating the hull form via the inclusion of waterlines, buttock lines and section lines shown on profile, plan and end views.

Lines plan


To learn to one side.


Load Line


London Maritime Arbitrators Association


Liquefied Natural Gas

LNG carrier

Vessel designed to transport natural gas in liquefied form.

LNG carrier


Length Overall of the vessel

Load eater line

The water line when the ship is loaded.

Load line markings

Markings on the ship's side defi ning the minimum freeboard allowable in different ocean areas and different seasons of the year. Also known as Plimsol mark.

Load line markings


A storage compartment in a ship.


A man who lays out the ship's lines in the mold loft and makes the molds or templates therefrom.

Log book

A continuous operating record of a ship kept by one of its officers. In it are recorded daily all important events occurring on board, also the condition of the weather, the ship's position and other data.


A ship which is slightly unstable in the vertical position will heel until the GZ curve becomes zero. It is said to loll and the angle it takes up is the angle of loll.

Lo-lo (lift on-lift-off)

Cargo handling method by which vessels are loaded or unloaded by either ship or shore cranes.


A line in the fore and aft direction parallel to the centreline. Also refers to a longitudinal stiffener running parallel (or nearly parallel) to the centreline.

Longitudinal bulkhead

A partition wall of planking or plating running in a fore-and-aft direction. Oil tankers are required to have at least one fore-and-aft bulkhead in the cargo oil space. Fore-and-aft bulkheads are very common on warships.

Longitudinal centre of buoyancy (LCB)

The fore and aft location of the centre of buoyancy.

Longitudinal centre of buoyancy (LCB)

Longitudinal centre of gravity (LCG)

The fore and aft location of the centre of gravity.

Longitudinal stability

The stability of a ship for rotation (trim) about a transverse axis.


A laborer who works at loading and discharging cargo.


The man stationed aloft or in the bows for observing and reporting objects seen.


The part of an oar between the blade and handle. The reflection of a light below the horizon due to certain atmospheric conditions.


To unfurl.


Lines of Position


A small opening to permit the passage of air for the purpose or ventilation, which may by partially or completely closedby the operation of overlapping shutters.


Last Open Water


Liquefied Petroleum Gas

LPG carrier

LPG carrier

Vessel designed to transport petroleum gas in a form of butane or propane.


Long Range Identification & Tracking of Ships




Life Saving Appliances


Lashed Secured Dunnaged


Liner Terms


Lost Time Injury


Loss Time Injury Frequency

Lubber line

The black line parallel with ship's keel marked on the inner surface of the bowl of a compass, indicating the compass direction of the ship's head.

Lug pad

A projection on deck with hole for fastening a block for a lead.


The sudden heave of the ship.


Low Water


Lost Workday Case


Laycan (Layday Canceling Date)

Lyle gun

A gun used in the life-saving services to throw a life line to a ship in distress or from ship to shore and used when a boat cannot be launched.




Motor Vessel


Term covering main engines, auxiliary engine room machinery(e.g.,pumps, compressors, etc.,) in addition to other installed plant (e.g., hydraulics, air-conditioning plant, lift machinery, etc.,) and deck machinery (e.g., mooring winches, windlasses, etc.).


A steel fitting formed by a flat doubler plate and vertical steel member containing a circular opening.


Internal space dedicated to the storage of munitions (shells, surface-to-air missiles, etc.) in a naval vessel.


Marine Accident Investigation Branch

Main beam

The main longitudinal beam on a ship, running down the center line and supports as a rule by king posts. Sometimes there are two main beams, on each side of the center line.

Main body

The hull exclusive of all deck erections spars, streaks, etc., the naked hull.

Main breadth line

The greatest width of a ship amidships. If a ship's sides tumble home, the main breesth line will be considerably below the bulwarks.

Main deck

The main continuous deck or principal deck of a vessel

Main mast

The principal mast of a vessel.

Main mast

Make colors

Hoisting the ensign at 8 a.m. and down at sunset.

Make the course good

Steering; keeping the ship on the course given (no lazy steering).

Make the land

Landfall. To reach shore.

Make water

To leak; take in water.


Maximum size of container and bulk vessels (in terms of draught) that can cross the Malacca Straits. The Malacca-max reference is believed to be today the absolute maximum possible size for future container vessels (approximately 18,000 TEU).

Man ropes

Ropes hung and used for assistance in ascending and descending.


The perforated. Elevated bottom of the chain locker which prevents the chains from touching the main locker bottom, and allows see page water to flow to the drains.


A hole in a tank, boiler or compartment on a ship, designed to allow the entraned of a man for examination, cleaning and repairs.



A framed opening in the deck of a vessel which primarily provides access for a man.

Manhole cover

A cover which seals a manhole and is usually designed to lock in place by twisting or using a centerbolt, studbolts, or dogs.

Manhole cover


A casting or chest containing several valves. Suction or discharge pipes from or to the various compartments, tanks, and pumps are led to it, making it possible for several pumps to draw from or deliver to a given place through one pipe line.


Rope made from the fibers of the abaca plant.

Margin plate

A longitudinal plate whick closes off the ends of the floors along the widship section


Pointed iron implement used in separating the strands of rope in splicing, marling, etc.


To put a person ashore with no means of returning.


To join two ropes ends so that the joint will run through a block, also to place two ropes alongside each other so that both may be hauled on at the same time.


A spar or hollow steel pipe tapering smaller at the top, placed on the center line of the ship with a slight after rake. Masts support the yards and gaffs. On cargo vessels they support cargo booms.

Mast hole

A hole in the deck ti receive a mast. The diameter of the hole is larger than the mast for the purpose of receiving two rows of founded wedges to hole the mast in place.

Mast step

The frame on the keelson of boat (does not apply on ships) to which the heel of a mast is fitted.

Mast table

A structure built up around a mast as a support for the cargo boom pivots.


A term for the captain, a holdover from the days when the captain was literally, and legally, the "master" of the ship and crew. His word was law.


The top part of the mast.

Masthead light

The white running light carried by steam vessel underway on the foremast or in the forepart of the vessel.


Slabs, usually constructed of timbers, which are placed on the deck of a vessel for the purpose of supporting and distributing the weight of heavy loads. back


Slabs, usually constructed of timbers, which are placed on the deck of a vessel for the purpose of supporting and distributing the weight of heavy loads.


Merchant Broker


Minimum Breaking Load


Multi-Buoy Moorings


Maritime Coastguard Agency (United Kingdom)


Marine Diesel Oil


Maritime Environment Pollution Comittee


Merchant Ship Search & Rescue Manual

Mess gear

Equipment used for serving meals.


A light line used for hauling over a heavier rope or cable.


A member of the steward's department who served meals to officers and crew.


A space or compartment where members of the crew eat their meals, a dining room in which officers eat their neals is called a wardroom messroom.


The intersection of successive vertical lines through the centre of buoyancy as a ship is heeled progressively. For small inclinations the metacentre is on the centreline of the ship.


Metacentric diagram

A plot showing how the metacentre and centre of buoyancy change as draught increases.

Metacentric diagram

Metacentric height (GM)

The vertical separation of the metacentre and the centre of gravity as projected on to a transverse plane.

Metacentric height (GM)

Mezzamine financing

A mix of financing instruments, including equity, subordinated debt, completion guarantees, and bridge financing, the balance of which changes as the risk profile of a project changes (that is, as a project moves beyond construction into operation).


Medical First Aid Guide

Middle body

That part of a ship adjacent to the midship section. When it has a uniform cross section throughout its length, with its water lines parellel to the center line, it is called the parellel middle body.


The middle of the vessel.

Midship area coefficient (CM)

One of the coefficients of fineness. It is the ratio of the underwater area of the midship section to that of the circumscribing rectangle.

Midship area coefficient (CM)

Midship beam

The longest beam transverse or longitudinal of the midship of a vessel.

Midship frame

The frame at midship, which is the largest on the vessel.

Midship section

Fully dimensioned sectional drawing of both hull and superstructure principal structural members at the midships station.


Minimum/Maximum (cargo quantity)


Marine Information Object


Maritime Mobile Service Identity


Merchant Navy Liaison Officer


Man Overboard


Management Of Change


Mobile Offshore Drilling Unit


More or Less Charterers Option


A pattern or template. Also a shape of metal or wood over or in which an object may be hammered or pressed to fit.

Mold loft

The large enclosed floor wher the lines of a vessel are laid out and the molds or templates made.

Molded breadth

The greatest breadth of a vessel, measured from the heel of frame onone side to heel of frame on the other side.

Molded depth

The extreme height of a vessel amidships, from the top of the keel to the top of the upper deck beam.

Molded depth

Molded depth

The distance from the top of the keel to the top of the upper deck beams amidships at the gunwale.

Molded line

A datum line from which is determined the exact location of the various parts of a ship. It may be horizontal and straight as the molded base line, or curved as a molded deck line or a molded frame line. These lines are determined in the design of a vessel and adhered to throughtout the construction. Molded lines are those laid down in the mold loft.

Molding edge

The edge of a ship's frame which comes in contact with the skin , and is represented in the drawings.


A breakwater used as a landing pier.


More or Less Owners Option

Monkey fist

A knot worked into the end of a heaving line (for weight).

Monkey island

A flying bridge on top of a pilothouse or chart house.

Monkey tail

A curved bar fitted ti the upper, after end of a rubber, and used as an attachment for the rubber pendants.


Securing to a dock or to a buoy, or anchoring with two anchors.

Mooring line

Cable or hawse lines used to tie up a ship.

Mooring pipe

An opening through which hawse lines pass.


A hole cut in any material to receive the end or return of anoter piece.

Mother Carey's chickens

Small birds that foretell bad weather and bad luck.

Moulded breadth

Greatest breadth of a hull measured between inner surfaces of the side shell plating.

Moulded breadth


Small stuff seized across a hook to prevent it from unshipping (once hooked, mousing keeps the hook on).


Maritime Safety Committee


Material Safety Data Sheet


Maritime Safety Information


Maximum Securing Load


Mean Sea Level


Metric Ton (i.e. 1,000 kilos / 2204.6lbs)


Medical Treatment Case


Marine Terminal Operators Training System


Marine Technical Sub-Committee

Mud scow

A large, flat bottomed boat used to carry the mud from a dredge.


The vertical bar dividing the lights in a window.

Mushroom anchor

An anchor without stock and shaped like a mushroom.




Not Always Afloat But Safely Aground

Nantucket sleigh ride

A term for what frequently happened to Nantucket whalers when they left the whaling ship in a small boat to go after a whale. If they harpooned the whale without mortally wounding it, the animal took off with the whaleboat in tow.


Navigation and Routeing Sub-Committee

Nautical mile

Unit of distance used in marine navigation. (International nautical mile = 1.852 km. 6076.12 ft, 1.1508 land miles.) The international nautical mile is equivalent to the average linear distance over 1 minute of latitude arc at 45° latitude at sea level.


National Cargo Bureau


National Chemical Emergency Centre


Norwegian Centre for Maritime Medicine


Non Discharge Area

Neobulk cargo

Non-, or economically not feasible, containerizable cargo such as timber, steel, and vehicles.


The mythical god of the sea.


Implies that cargo is presented stacked in the contour of similarly shaped cargo, it may be likened to a stack of plates.

Net registered tonnage

A formula-derived measure of the internal (enclosed) volume in a vessel except spaces for machinery, navigation and accommodation. Net tonnage is always less than the gross tonnage.

Net tonnage

The cubical space available for carrying cargo and passengers.


A rope network.


Non Indigenous Species


Noxious Liquid Substances


(Detention). If loading completed sooner than expected, then saved days will not be added to discharge time allowed.

Nonvessel operating common carrier (NVOCC)

A cargo consolidator in ocean trades who buys space from a carrier and resells it to smaller shippers. The NVOCC issues bills of lading, publishes tariffs, and otherwise conducts itself as an ocean common carrier, except that it does not provide the actual ocean or intermodal service.

Non-watertight door

A term applied to a door that is not constructed to prevent water under pressure from passing through.


Notice of Readiness

Not under command

Said of a vessel when unable to maneuver.

Not under control

Same as not under command.


National Pollutant Discharge Elimination System


Notice of Proposed Rule Making


Net Registered Tonnage


Non Tank Vessel Response Plan


Not Under Command


New York Produce Exchange




Material used for caulking the seams of vessels and made from the loose fibers of old hemp rope.

OBO (Oil-bulk ore (carrier))

Vessel designed for the transportation of oil and/or bulk ores.


On Board Quantity




Oil Company International Marine Forum


Oil Content Monitor


Oil Discharge Monitoring & Control Systems


Oil Discharge Monitoring Equipment


Ozone Depleting Substances


Occupational Exposure Limit


Office of Foreign Assets Control

Off and on

Standing toward the land and off again alternately.

Officer of the watch

The officer in charge of the watch.


Are given in feet, inches and eights of an inch. They are taken from large body plans and given the horizontal distance from the center line to the molded frame line on each of the water lines, which are usually spaced 2′-0" apart. Offsets also give the height of each buttock above the baseline at each frame< the heights of decks from the base line, the location of longitudinals and stringers by half breadths and heights, or heights above the base line intersecting the molded frame lines, and all dimensions such that the entire molded form of a ship and the location of all membersof the structure are definitely fixed.



Dimensional co-ordinates of a hull form, (referenced to the moulded baseline, centreline and transom or AP) usually presented in tabular format.


Offshore Floating Group


A molding with a concave and convex outline like an S.


Offshore Hose Guidelines


Officer in Charge

Oil bag

A bag filled with oil and triced over the side for making a slick in a rough sea (to keep seas from breaking).

Oil tanker

Vessel designed for the transportation of liquid hydrocarbons in bulk.

Oil tanker


Waterproof clothing.


Having the property of resisting the passage of oil.

Oiltight bulkhead

A partition of plating reinforced where necessary with stiffering bars and capable of preventing the flow of oil under pressure from one compartment to another. The riveting must be closer spaced than in watertight work and special care must be taken with the calking.

Old man

A piece of heavy bar iron bent to the form of a Z. One leg of the Z is bolted to the material that is to be drilled, and the drill top placed under the other leg and adjusted so the "old man" holds the drill against the material.


Offshore Marine Committee


Offshore Maritime Operations Group

On board

On or in a ship.

On deck

On the upper deck, in the open air.

On report

In trouble.

On soundings

Said of a vessel when the depth of water can be measured by the lead (within the 100 fathom curve).


Office of Naval Initiative


Owners Option


Oil Pollution Act


Oil Pollution Preparedness, Response and Cooperation

Ordinary seaman

The beginning grade for members of the deck department. The next step is able bodied seaman.

Orlop deck

The lowest deck in a ship.


Open Reporting System


Open Shelter Deck


Offshore Terminal Forum

Out of trim

Not properly trimmed or ballasted (not on even keel; listing).


In a direction towards the side of the ship.


Away from the keel or center of a vessel on either side.

Outboard profile

A plan representing the longitudinal exterior of a vessel, showing the starboard side of the shell, all deck erections, masts, yards, rigging, rails, etc.


The extreme deck fore and aft measurement of a vessel.


Outside, over the side of a ship into the water.


The carriage of cargo beyond the port for which it was intended.


Same as counter


Get gear in condition for use; to separate the blocks of a tackle to lengthen the fall (ready for use again).


Said of a vessel when she is passing or overtaking another vessel.


Offshore Vessel Inspection Database


Offshore Vessel Inspection Questionnaire


Offshore Vessel Management and Self Assessment


Oil Water Separator




The combination of a substance or element like wood, iron, gasoline, etc, with oxygen. The process is fundamentally the same whether wood is consumed with fire or iron is turned into rust (iron oxide). In welding the oxygen of the air forms an oxide with the molten metal, thus injuring the quality and strength of the weld.

Oxter plate

The name of a plate that fits in the curve at the meeting of the shell plating with the top of the stern post and which is fastened there to.



Men who fit lamp wicking, tarred felt or other material between parts of the structure to insure water or oil tightness.

Pad eye

A fitting having an eye integral with a plate or base in order to distribute the strain over a greater area and to provide ample means of securing. The pad may have either a "worked" or a "shackle" eye, or more than one of either or both. The principal use of such a fitting is that is affords means for attaching rigging, stoppers, mlocks, and other movable or portable objects. Pas eyes are also known as lug pads.


A short piece of rope secured in the bow of a small boat used for making her fast.

Painting beams

The transverse beams that tie the painting frames together.

Painting frames

The frames in the fore peak, usually extra heavy to withstand the panting action of the shell plating.

Pair masts

A pair of cargo masts stepped on eith side of the center line, with their heads connected by spans.


One of the interior shores for steadying the neams of a ship while building.


A flat wooden or plastic platform onto which cargo may be strapped or lashed which simplifies handling via cranes and forklift vehicles.


Pallet carrier

Cargo vessel specially designed or adapted for the transportation of pallet-borne cargoes.

Pallet carrier

Pallet carrier

Palm and needle

A seaman's sewing outfit for heavy work.

Panamax Market

category of vessels notionally at the dimensional limits for transiting the Panama canal.


The pulsation in and out of the bow and stern plating as the ship alternately rises and plunges deep into the water.

Panting stringer

Horizontal deep-web side structural member used for strengthening bow structure prone to panting loads.

Panting stringer

Parallel midbody

Midship portion of a hull within which the longitudinal contour is unchanged.


A water plane with a protecting wing placed on bottom forward end of the keel stem. Also a special type of waterkite which, when towed wth wire rope from a fitting on the forefoot of a vessel, operates to ride out from the ship's side and deflect mines which are moored in the ppath of the vesse;, and to cut them adrift so that they will rise to the surface where they may be seen and destroyed.


Piracy Attack Risk Surface


To break.

Partial bulkhead

A term applied to a bulkhead that extends only a portion of the way across a compartment. They are generally erected as strength members of the structure.


Similar pieces of steel plate, angles or wood timbers used to strengthen and support the mast where it passes through a deck, or placed between deck beams under machinery bed plates for added support.

Pass a line

To reeve and secure a line.

Pass a stopper

To reeve and secure a stopper (hold a strain on a line while transferring it).

Pass down the line

Relay to all others in order (a signal repeated from one ship to the next astern in column).

Pass the word

To repeat an order for information to the crew.

Passenger vessel

A vessel which carries more than 12 passengers.


Past Us


To fill the seams of a vessel with pitch.

Pay off

To turn the bow away from the wind; to pay the crew.

Pay out

To slack out a line made fast on board (let it out slowly).


Paying out, slackening away on a rope or chain. Also the operation of filling seams between planks after calking, with melted pitch or marine glue, etc.


Period of Charter


Privately Contracted Armed Security Personnel


Part Cargo




Plan Do Check Act


Per Day Pro Rata


See Fore Peak and after Peak.

Peak tank

Tank in the forward and after ends of a vessel. The principal use of peak tanks is in trimming The ship. Their ballast is varied to meet required changes in trim. Should the after hold be empty, the vessel would ride so high that the propeller would lie half out of water and lose much of its efficiency. Filling the afer peak tank forces the propeller deeper into the water.


To round off or shaoe an object, smoothing out burrs and rough edges. (Nown) The lesser head of a hammer. It is termed ball when it is spherical, cross when in the form of a rounded edge ridges at right angles to the axis of the handle, and sraight when like a ridge in the plane of the handle.

Pelican hook

A hinged hook held closed by a ring and used to provide the quick release of an object which it holds.

Pelican hook


A length of rope, usually having a thimble or block spliced into the lower end for hooking on a tackle.




Per Diem By the Day

Permanent ballast

Ballast material (usually solid material) which cannot be discharged or transferred by pump or by other means and which is used for attaining design draft and trim.

Permanent dunnage

Strips of timber fixed to the frames of a ship to keep cargo away from the sides of the ship to avoid damage and condensation.

Perpendicular, after

A line perpendicular to the keel line, drawn tangent to the after contour of the stern.


Piracy Focus Group


Per Hatch Per Day

Pier head jump

Making a ship just as it is about to sail.


A pointed spar driven into the bottom and projecting above the water; when driven at the corners of a dock, they are termed fender piles.


Stealing of cargo.


Vertical column used to provide support to overhead deck structure.


Vertical columns supporting the decks. Also called stanchions.

Pilot boat

A power or sailing boat used by pilots (men who have local knowledge of navigation hazards of ports).

Pilot house

A house designed for navigational purpose. It is usually located forward of the midship section and so constructed as to command an unobstructed view in all directions except directly aft along the center line of the vessel, where the smokestack usually interferes.

Pilot rudder

A small rudder fastened to the after part of the regular rudder, which by a mechanical attachment pulls the main rudder to either side.


The metal axle of a block upon which the sheave revolves.


A metal pin secured to the rubber, which is hooked downwardinto the qudgeons on the stern post, and affords an axis of oscillation as the rubber is moved from side to side for steering.


Pipe layer

Vessel designed for the laying of pipelines on the sea bed.

Pipe layer

Pipe stanchion

A steel deck fitting consisting of a vertical post with angled bracket(s) on one side, welded to a doubler plate, which is welded on the deck of a vessel to restrain the movement of cargo, such as pipe.


A tar substance obtained from the pine tree and used in paying the seams of a vessel. Motion of vessel.


The oscillatory vertical motion of a vessel forward and aft in a seaway.



Areas of corrosion.


To braid; used with small stuff.


A drawing prepared for use in building a ship.


Broad planks used to cover a wooden vessel's sides, or covering the deck beams.

Plate, furnaced

A plate that requires heating in order to shape it as required.


A partial deck.

Platform deck

Deck which does not contribute to the overall longitudinal strength of a vessel.


The steel plates which form the shell or skin of a vessel.


Freedom of movement.


Pipeline End Manifold

Plimsoll mark

The primary loadline mark which is a circle intersected by a horizontal line accompanied by letters indicating the authority under which the loadline is assigned.

Plimsoll mark


A wooden wedge fitting into a drainage hole in the bottom of a boat for the purpose of draining the boat when she is out of water.

Plummer blocks

Supports for a shaft (such as the propeller shaft).

Plummer blocks

Plummer blocks


A ship is said to plunge when it sinks bow or stern first through loss of longitudinal stability.



Private Maritime Security Contractor


Philippine Overseas Employment Administration


To taper the end of a rope; one of the 32 divisions of the compass card. To head close to the wind.


The property possessed by electrified bodies by which they exert opposite forces in opposite directions. The current in an electrical circuit passes from the positive to the negative pole. In welding, more heat is generated on the positive pole than on the negative one, so that the welding rod is generally made the negative electrode.


Flat-bottomed floating structure with a shallow draught.


Sharing of cargo or the profit or loss from freight by member lines of a liner conference.


The structure or raised deck at the after end of a vessel.

Poop deck

A partial deck at the stern above the main deck, derived from the Latin "puppio" for the sacred deck where the "pupi" or doll images of the deities were kept.


An opening in a ship's side, such as an air port, or cargo port.


Those pieces of timber which are fixed perpendicularly between the ship's bottom and the bilgeways at the foremost and aftermost parts of the ship, to support her in launching.


(1) Pertaining to the left-hand side of a vessel. (2) Term used for small windows in the marine context.

Port gangway

An opening in the side plating, planking, or bulwark for the purpose of providing access through ehich people may board or leave the ship or through which cargo may be handled.

Port hole

An opening in the ship's shell plating.

Port lid

A shutter for closing a port hole in stormy weather. It is hung by top hinges.

Port of Registry

Port in the country under whose flag a vessel is legally registered.

Port side

The left hand side of the ship looking forward.

Port State Control

The examination of vessels for compliance with IMO Conventions and resolutions by state authorities.

Pouring oil on troubled waters

Heavy-weather practice of pouring oil on the sea so as to form a film on the surface, thus preventing the seas from breaking. To smooth out some difficulty.


Permanent Partial Disability


Personal Protective Equipmeny


A permit by the port doctor for an incoming vessel, being clear of contagious disease, to have the liberty of the port.


License or permission to use a port


Presentation to the customs authorities of export or import declarations prior to the clearance of goods.


A rope used for additional support or for additional securing, e.g., preventer stay.

Prick punch

A small hand punch used to make a very small indentation or prick in a piece of metal.


Small marlinespike.

Privileged vessel

One which has the right of way.

Product tanker

Tanker designed for the transportation of a variety of hydrocarbon and chemical liquids with elaborate pumping and safety systems.

Prolonged blast

A blast of from 4 to 6 seconds' duration.


A propulsive device consisting of a boss or hub carrying radial blades, from two to four in number. The rear or driving faces of the blades form portions of an approximately helical surface, the axis of which as the center line of the propeller shaft.


Propeller arch

The arched section of the hull above the propeller.


The part of the bow from the load water line to the top of he bow.


Pounds Per Square Inch


Pounds Per Square Inch Gauge


Perils at Sea Revision


Ports & Termincal Committee


Permanent Total Disability

Pull-out manoeuvre

A manoeuvre used to demonstrate the directional stability of a ship.

Pump dale

A pipe to convey water from the pump discharge through the ship's side.

Punch, center

A small punch used to indent a piece of metal for centering a drill.


A rectangular flat- bottomed boat used by vessels for painting the ship's side and general use around the ship's water line, fitted with oar-locks on each side and usually propelled by sculling.


A tackle (blocks and falls).

Pusher tug

Tug designed for or engaged in pushing barges from behind.

Pusher tug

Pusher tug

Put to sea

To leave port.

PV valve

Pressure vacuum relief valve; a valve which automatically regulates the pressure or vacuum in a tank.

PV valve

PV valve

PV valve


Ports and Waterways Safety Act



Quality, Health, Safety & Environment


A fitting on the rubber head to which the steering chains are attached.


Quadrant-shaped flat plate assembly mounted horizontally on top of a rudder stock for to which steering cables/chains are attached in vintage vessels or small craft.


Restricted or prohibited intercourse due to contagious disease.


That portion of a vessel's side near the stern.


A side of a ship aft, between the main midship frames and stern. Also a sidde of a ship forward, between the main frames and the stem.

Quarter deck

A term applied to the after portion of a weather deck. In a warship that portion allotted to the use of the officers.

Quarter deck

Full-width raised hull section and deck extending from the aft shoulder to the stern.

Quartering sea

A sea on the quarter (coming from a side of the stern).


Living spaces for passengers or personnel. It includes staterooms, dining salons, mess rooms, lounging places, passages connected with the foregoing, etc., individual stations for personnel for fire or boat drill, etc.

Quarters bill

A vessel's station bill showing duties of crew.


An artificial wall or bank, usually of stone, made toward the sea at the side of a harbor or river for convenience in loading and unloading vessels.



A depression or offset designed to take some other adjoining part, as for example the rabbet in the stem taking the shell plating.


The upper edge of the bulwarks.


Horizontal parallel tubing forming a safety barrier at edges of decks.

Rail-mounted gantry (RMG) or rail-mounted container gantry crane

Rail-mounted gantry crane used for container acceptance, delivery, and stacking operations in a container yard.


The forward pitch of the stem. The backwark slope of the stern.


Risk Assessment Matrix

Ram bow

A bow protruding undernearth the water line considerable forward of the fore-castle deck.


Hinged platform permitting the loading/discharge of vehicles or movement between decks of vehicles aboard Ro-Ro vessels.


The maximum distance a vessel is capable of attaining at its normal

Range, galley

The stove situated in the galley which is used to cook the food. The heat may be generated by coal, fuel oil, or electricity.


A short length of small rope "ratline stuff" running horizontally across shrouds, for a ladder step.


Raster Chart Display System




The horizontal distance that a crane or lifting appliance can cover, measured from its axis of rotation.


A steel rod which connects an above deck valve handle to a below deck valve.


A steel rod which connects an above deck valve handle to a below deck valve.


Enlarging a hole by the means of revolving in it a cylindrical slightly tapered tool with cutting edges running along its sides.


Regional Cooperation Agreement of Combating Piracy & Armed Robbery Against Ships in Asia


To reduce the area of a sail by making fast the reef points (used in rough weather).


Refrigerated container or vessel designed to transport refrigaeated or frozen cargo.


To pass the end of a rope through any lead such as a sheave or fair lead.

Refrigerated vessel

Vessel designed for the transportation of refrigerated perishable


The ship's certificate determining the ownership and nationality of the vessel. Relieving tackle. A tackle of double and single blocks rove with an endless line and used to relieve the strain on the steering engine in heavy weather or emergency.


To transfer containers from one ship to another.


Any clearance allowed back of the cutting edge to reduce friction whether on top, bottom or wall of the tread.

Research vessel

Vessel designed for oceanographic or fisheries research.


Reserve buoyancy

Watertight volume of a vessel above the waterline.

Reverse frame

An angle bar placed with its heel against another angle additional strength. The flanges of deck stiffeners always bace outboard.

REVERSIBLE (Detention)

If loading completed sooner than expected at load port, then days saved can be added to discharge operations.


Rigid inflatable boat.

Rigid inflatable boat


A longitudinal strtip of timber following the curvature of a vessel and bolted to its ribs to hold them in position and give stability to the skeleton while building.


To lie at anchor; to ride out; to safely weather a storm whether at anchor or underway.

Ride control

System(s) employing active hydrodynamic foils or deflectors installed to vary the attitude and vertical motions of the hull in high-speed vessels.

Rider frame

Any frame riveted or welded on another frame for the purpose of stiffening it.

Rider plates

Bed plates set on top of the center keelson, if fitted, for the pillars to rest on.


A general description of a vessel's upper works; to fit out.


A term used collectively for all the ropes and chains employed to support the masts, yards, and booms of a vessel, and to operate the movable parts of same.


To return to a normal position, as a vessel righting after heeling over.


A bolt fitted with a ring through its eye, used for securing, running, rigging, etc.


Radar Information Overlay


A disturbance of surface water by conflicting current or by winds.

Rise and shine

A call to turn out of bunks.

Rise of bottom

See Deadrise.

Rising floors

The floor frames which rise fore and aft above the level of themidship floors.


A metal pin used for connecting two or more pieces of material by inserting it into holes punched or drilled in the pieces. The end that bears a finished shape is called the head and the end upon which some oretation is performed after its insertion is called the point. Small rivets are "driven cold", i.e. without heating, and large ones are heated so that points may be formed by hammering.

Rivet spacing

A term applied to the distance between the centers in a row of rivets. This distance usually consists of a multiple of the rivet diameter, and depends on whether oiltightness, watertightness or strenght is to be the governing requirement.

Riveting chain

A term applied to two or more rows of rivets that have their centers opposite each other. A line drawn perpendicular to the edge of the plate through the center of a rivet in one row will also pass through the centers of the corresponding rivets in the other rows.


Recommendations for Manifolds of Refrigerated for Gas Carriers for Cargoes


Raster Navigational Chart


Royal National Lifeboat Institution

Roaring forties

That geographical belt located approximately in 40 degrees south latitude in which are encountered the prevailing or stormy westerlies.


Remaining On Board


Motion of the ship from side to side, alternately raising and lowering each side of the deck


Roller fairleader

A block, ring, or other fitting through which passes a line or the running rigging on a ship to prevent chafing.

Roller Fairleader

Roller Fairleader

Roller Fairleader

Rolling chocks

Same as bilge keel.


Vessel designed with combined Ro-Ro and passenger capacity.


Roll-on Roll-off. Method of cargo transfer between vessel and shore in which cargo is driven on/off using fork-lift, primemover/ trailer combinations, etc.


Recruitment Placement Services


Release Retrieval System


Revenue Ton (i.e. 1.0 metric Ton or 1.0 cubic meter, whichever is greater). The overall RT is calculated on a line by line basis of the Packing List using the largest amount. The overall freight liability is calculated on the total RT amount, multiplied by the freight rate.

Rubber-tired gantry (RTG) or rubber-tired container gantry crane

Gantry crane on rubber tires typically used for acceptance, delivery, and container stacking at a container yard.


A protective railing on the hull of a vessel which is used for fendering.


A swinging flat frame hung to the stern post of a ship, by which the ship is steered.


Rudder bands

The bands that extend on each side of a rudder to help brace and tie ii into the pintles.

Rudder chains

The chains whereby the rudder is fastened to the stern quarters. They are shackld to the rudder by bolts just above the water line, and hang slack enough to permit free motion of the rudder. They are used as a precaution against losing a rudder at sea.

Rudder flange

The flange which ties the main part of the rudder to the rudder stem. It may be horizontal or vertical.

Rudder frame

A frame within the inner shell, bolted through the letter into the main frame and shell, for the purpose of stiffening the rudder.

Rudder pintle

See Pintle

Rudder post

The vertical post in the stern of a vessel on which the rudder hangs.

Rudder stock

Vertical shaft connecting the rudder to the steering actuating system.

Rudder stock

Rudder stop

Fitting to limit swing of the rudder.

Rudder truck or case

The well in the stern which holds the rudder stock.


Rules for the Use of Force


The narrowing sides of a vessel aft where they meet at the hooding-ends.

Run down

To collide with a vessel head on.

Running lights

Those lights required to be shown at night aboard a vessel or a tow while underway.

Running lights

Those lights required to be shown at night aboard a vessel or a tow while underway.


Sailors' term for an old ship that needed a lot of paint and repairs.


Sacrificial anode

Anode of zinc attached to the immersed parts of a hull to prevent deterioration of the hull steel through electrochemical reaction.

Sacrificial anode

Sacrificial anode

Safety of Life at Sea (SOLAS)

A statutory regulation of IMO dealing with the safety of life at sea.


Said of a ship which has been strained so that the bottom drops lower in the middle than it is at stem and stern. Opposite of hogged.


A ship is said to sag if the forces acting on it make it bend longitudinally concave up. Sagging is the opposite of hogging.

Sailing free

Sailing other than close; hauled or into the wind (wind astern).


Single Anchor Leg Mooring

Salty character

A nautical guy, often a negative connotation.


To save a vessel or cargo from total loss after an accident; recompense for having saved a ship or cargo from danger.

Salvage tug

Large powerful and manoeuvrable vessel designed to tow and assist vessels needing assistance due to grounding, sinking or fire.


Substance Abuse and Mental Health Services Administration

Samson posts

Short heavy masts used as boom supports, and often used for ventilators as well.


Search and Rescue Transponder



Search And Rescue Transponder. A SART is a self contained, waterproof radar transponder intended for emergency use at sea. The radar-SART is used to locate a survival craft or distressed vessel by creating a series of dots on a rescuing ship's radar display. A SART will only respond to a 9 GHz X-band (3 cm wavelength) radar. It will not be seen on S-band (10 cm) or other radar.


Saturday P.M.


Safe Access to Vessels Working Group


Safe Berth


To climb up. A formation of rust over iron or steel plating.


A term applied to the dimensions of the frames, girders, plating, etc., that go into a ship's structure. The various classification societies publish rules from which these dimensions may be obtained.


Set of dimensions of a vessel's structure. (Structural dimensions.)


A method of cutting away two pieces so that they fit smoothly into each other to make one piece. They are fastened together by welding, bolting, riveting, etc.


Self-Contained Breathing Apparatus. Such an apparatus consists of a suitable face mask, combined with a hose and source of fresh air, generally in the form of a tank of compressed air. The SCBA may be incorporated into a full-body protection suit. It is important to recognise that use of a SCBA is not trivial, and they are not designed to be worn by those without training.




Speed Reduction and Bunker Consumption Algorithm


A large body of fish.


Another term for a deck cargo barge having a hull design of a flat bottom, square ended rakes, and usually with a deck cargo bin.

Screen bulkhead

A light bulkhead fitted between engine and boiler rooms, designed to keep dust and heat out of the engine room. Often built around the after ends of boilers.

Scrieve board

A large section of flooring in the mold loft in which the lines of the body are cut with a knife. Used in making molds of the frames, beams, floor plates, etc.


Self-Containerd Underwater Breathing Apparatus


Any opening or tube leading from the waterway through the ship's side, to carry away water from the deck.



Scupper hose

A temporary canvas hose attached to the outside of a scupper hole, and reaching to the water, to conduct the water clear of the ship's side.

Scupper lip

A projection on the outside of the vessel to allow the water to drop free of the ship's side.

Scupper opening

A hole longer than an ordinary scupper with vertical bars, placed on the side of the ship at the deck line to allow deck wash to flow over the side of the vessel. Also called freeing port.

Scupper pipe

A pipe connected to the scupper on the decks, with an outlet through the side plating just above the water. The water thus diverted from the deck does not discolor the ship's side plating or damage the paint.


Openings in the side of a ship to carry off water from the waterways or from the drains.


A small opening, usually circular in shape, and generally fitted in decks to provide access as a manhole or for stowing fuel, water and stores. A cover or lid is fitted so that the scuttle may be closed when not in use. Also applied to the operation of opening a sea valve or otherwise, allowing the sea to enter a ship for the purpose of sinking her.

Scuttle butt

The designation for a container of the supply of drinking water for the use of the crew.

Scuttle butt story

An unauthoritative story (a tall story).

SD (or SID)

Single Decker


Seafarer Employment Agreement

Sea anchor

A drag (drogue) thrown over to keep a vessel to the wind and sea.

Sea chest

A sailor's trunk; the intake between the ship's side and a sea valve.

Sea dog

An old sailor.

Sea going

Capable of going to sea.

Sea lawyer

A seaman who is prone to argue, especially against recognized authority (big mouth).

Sea painter

A line leading from forward on the ship and secured to a forward inboard thwart of the boat in such a way as to permit quick release.


Costs charged for transporting goods over the sea. This does not cover any haulage or loading/discharging costs but the sea transport only.




Butt-strap of a seam.


Capable of putting to sea and able to meet sea conditions.


Sulphur (SOx) Emission Control Area


(1) General term for an extruded or fabricated structural member. [Alt profile.] (2) Transverse vertical plane through the hull perpendicular to the centreline.


To make fast; safe; the completion of a drill or exercise on board ship.

Secure for sea

Prepare for going to sea, extra lashing on all movable objects.


Ships Energy Efficiency Management Plan


To bind with small rope.


Self Discharging


Flag signaling with the arms.


System Electronic Navigational Chart

Serrated frame

Sometimes pieces of an angle iron are cut to allow for ventillation, reduce weight or as a shortcut that saves material in the vessel costruction. These cutouts may be spaced regularly-every few inches or so and the frame is called a serrated frame.

Set bolt

A bolt used as a drift to force another bolt out of its hole.

Set iron

Bar of soft iron used on the bending slab to bend frames to the desired shapes.

Set the course

To give the steersman the desired course to be steered.

Set up

To tighten the nut on a bolt or stud.

Set up rigging

To take in the slack and secure the standing rigging.

Sett piling

Reinforcing pilling in the ground beneath the ways.


To lower, sink deeper.


Stowage factor. Cubic space occupied by one ton (2,240 lbs/1,000 kgs) of cargo.


Special Forces Group


A link with a bolt fastened through its eyes, used for fastening chains and eye loops together.



Kenter shackle


Long, round, heavy forging connecting engine and propeller.

Shaft alley

Covered tunnels within a ship through which the tail shafts pass.

Shaft coupling

A flange on the end of a shaft section connecting two sections by bolts.

Shaft pipe

A pipe which pases through a hole in the stern post and through frames with a circular housing. In it are bearings on which the propeller shaft rotates.

Shaft strut

A brachet supporting the after end of the propeller shaft and the propeller in twin or multiple screwed vessels having propeller shafts fitted off from the center line.

Shaft tunnel

Same as shaft Alley.

Shake a leg

An order to make haste.

Shakedown cruise

A cruise of a new ship for the purpose of testing out all machinery, etc. Shank. The main piece of the anchor having the arms at the bottom and the Jew's harp at the top.


The practice of obtaining a crew by means of force. Crews were hard to get for long voyages, and when the unwilling shipmate regained consciousness, he found himself bound for some remote port, such as Shanghai. One who is forced to do something against his will.


Long bar of constant cross section such as channel, T-bar, angle bar, etc.

Shape a course

To ascertain the proper course to be steered to make the desired point or port. Shark's mouth. The opening in an awning around the mast.


Consists of cutting, bending and forming astructural member.

Shear legs

Usually two or more timbers or spars erected in the shape of an A-frame with lower ends spread out and upper ends fastenes together, from which lifting tackle is suspended. Used fro raising and moving heavy weights where a crane or derrick is not available.

Shear line

A line at which a shearing cut is to be made.


Large machine for cutting plates and shapes.


The wheel of the block over which the fall of the block is rove.

Shed (also see warehouse)

Covered area for the reception, delivery, consolidation, distribution and storage of cargo. Note: A warehouse usually points at longer term storage, whereas a shed usually is used for shorter term storage.


Upward longitudinal curvature of the upper deck.

Sheer plan

A vertical lngitudinal midship section of a vessel, showing plan, elevation and end view, on which are projected various lines as follows: Water line, diagonal line, buttock and bow lines, mainbreadth lines, top-breadth lines, top side sheer lines.

Sheer rail

A rail surrounding a ship on the outside, under the gunwale, on small vessels called guard rail.

Sheer strake

The uppermost strake (line) of side shell plating immediately adjacent to the strength deck.


The rope used to spread the clew of head sails and to control the boom of boom sails.


The casing of a block within which the sheave revolves.

Shell expansion

A plan showing the shapes and sizes of all plates of the shell plating.

Shell landings

Point on the frames showing wher the edges of the shell plates come.

Shell plating

See plating.

Shelter deck

A term applied to a deck fitted from stem to stern ona relatively light superstructure. The main deck.


Sundays/Holidays Excluded

Shift of butts

A term applied to the arrangement of the butt joints in plating. These joints in shell plating should be so shifted that the adjacent strakes of plating have their butts at least two frame spaces apart.

Shifting beam

A portable beam fitted in a hatchway for the purpose of supporting the hatch covers. The ends of the beams are fitted in slotted carriers attached to the inside of the hatchway coamings.


A piece of metal or wood placed under the bedplate or base of a machine or fitting for the purpose of truing it up. Also applied to pieces placed in slack spaces behind or under frames, plates or planks to preserve a fair surface.


Sundays/Holidays Included


To enlist; to send on board cargo; to put in place; to take on board.

Ship chandler

An individual or company selling equipment and supplies for ships.

Ship routing

An attempt to guide a ship into areas where it will experience less severe weather and so reduce passage times.

Ship's log

See Log Book

Ship's tackle

All rigging and so forth used on a ship to load or unload cargo.

Ships time

Ships time was counted by the half hour, starting at midnight. A half hour after twelve was one bell; one o'clock, two bells; and so on until four o'clock, which was eight bells. The counting then started over again, with 430 being one bell.


A piece of plank put under a shore where there is no groundway.


One of the many wooden props by which the ribs or frames of a vessel are external supperted while building, or by which the vessel is held upright on the ways.

Short stay

When the scope of chain is slightly greater than the depth of water.

Short ton

American ton (2000 lbs). 0.9072 tonnes.


Without sufficient crew.


A short length of chain, usually 15 fathoms (90 feet). (Method of measuring chain.)

Shove in your oar

To break into a conversation.


Side stays from the masthead to the rail..

Shuttle tanker

Moderate sized tanker designed for the regular short-haul transport of oil between FPSO vessels or single point mooring buoys and coastal refinery terminals.

Side keelson

A beam placed on the side of the hull about two-thirds the distance from the center line to the bilgeway. This ia uesd as a stiffener logitudinally for the flat bottom of a vessel.

Side lights

The red and green running lights, carried on the port and starboard sides respectively, of vessels under-way.

Side loader

A lift truck fitted with lifting attachments operating to one side for handling containers.

Sight edges

The edges of plating that are visible are called sight edges. The sight edge is on the outside of the shell, on the tops of decks and inner bottom plating, and on the opposite side from the stiffeners on bulkheads. The edge that is covered is called the landing edge.


Society of International Gas Tanker & Terminal Operators

Sing out

To call out.


Ship Inspection Report

Sister hooks

Two iron flatsided hooks reversed to one another.


The after part of the keel, upon which the stern post rests.



Beams sometimes fitted over the decks for the stowage of heavy boats or cargo.


Are bearers (timber or steel) positioned under cargo to enable fork lift handling at port, and for ease of rigging and lashing on board ship.


The plating of a ship. The inside skin is sometimes called the ceiling, the outside skin the case. It consists of steel plates laid in alternate inside and outside strakes.


The captain.

Sky pilot

A chaplain.


An erection built on a deck, having glass lights in its top and fitted over an opening in the deck for the purpose of admitting light and air to a compartment below.


Bale (capacity)


Safety Level Approach


The part of a rope hanging loose; the opposite of taut.

Slack water

The condition of the tide when there is no horizontal motion.


The impact of the hull, usually the bow area, with the sea surface when in waves.


Stability and Load Lines and on Fishing Vessels' Safety

Sliding ways

One of the structures on each side of and parallel to the keel, supporting the crandle under the bilgeways on which the vessel rests in launching. The sliding ways form the inclined plane down which the vessel slides, made of planks laid on blocks of wood.


To let go by unshackling, as a cable.

Slop chest

Stock of merchandise, such as clothing, tobacco, etc., maintained aboard merchant ships for sale to the crew

Slop chute

Chute for dumping garbage overboard.


An opening in the lower part of a bulkhead fitted with a sliding watertight gat or door having an operating rod extending to the upper deck or decks. These openings are useful in center line bulkheads, as in case of damage to one side of the ship the water may be quickly admitted to the other side before the ship is dangerously listed.


White-lead and tallow used on standing rigging.


Snappy, seamanlike; a smart ship is an efficient one.


Safety Management Certificate


A metal chimney or passage through which the smoke and gases are led from the uptakes to the open air.

Smothering lines

Pipe lines to a compartment for smothering a fire by steam or by a chemical.


Ship Mean Time


Society of Naval Architects and Marine Engineers (USA).



Handle that can be operated from both sides of a watertight door.


To cut a sharp bevel on the end of a stiffener or beam.


To check suddenly.


To twist a plate into an uneven warped shape on a mold.


Speed of Advance


Shipper Owned Container


Statement Of Facts

Soft plate

A plate put on over a break or hole, and secured with tap bolts. It is made watertight with a gasket such as canvas saturated in red lead.


Shipboard Occupational Health and Safety Program


International Convention for the Safety of Life at Sea

Sole patch

A plate fitted to the top of a foundation to which the base of a machine is bolted. Also a small plate fitted at the end of a stanchion.

Sole plate

A plate fitted to the top of a foundation to which the base of a machine is bolted. Also a small plate fitted at the end of a stanchion.


Standard Operating Procedure


To measure the depth of the water with a lead. Also said of a whale when it dives to the bottom.

Sound out a person

To obtain his reaction to something.


Measuring the depth of water or other liquid.


Measured depth of liquid contents in a tank.

Sounding pipe

Vertical pipe in oil or water tank, used to guide a sounding device when measuring the depth of liquid in tank.


An oil-skin hat with broad rear brim.


Safe Port


The distance between any two similar members, as the span of the frames. Also used to describe the length of a member between its supports, as the span of a girder.


A form of open-head wrench.


A pole used for a hoist or in scaffolding.


The radio operator.


Self-polishing copolymer antifouling paint.


To communicate with a vessel in sight.

Specific gravity

The ratio of the weight of a given volume of any substance to the weight of an equal volume of distilled water, and is found by dividing the first weight by the second. Since the distilled water weights approximately 62.4 pounds per cubic foot, any substance, a cubic foot of which weighs less than this, has a specific gravity of less than one, and will float on water. Any substance of greater weight per cubic foot has a specific gravity of more than one and will sink>


Specified details relating to the performance, operating conditions, construction and quality of an engineered item.

Spectacle frame

A single casting containing the bearings for and supporting the ends of the propeller shafts in a twin-screw vessel. It consists of arms of pear-shaped section extending outboard from each side of the center line of the ship to bosses, taking the bearings of the propeller shafts. Used in large metchant vessels in place of shaft struts or brackets.


The curve of a plate or strake as it narrows to a point.


To empty the wind out of a sail.


A method of uniting the ends of two ropes by first unlaying the strands, then interweaving them so as to form a continuous rope.


Self Protection Measures


Single Point Mooring


SPM Operating & Maintenance Guidelines


An addition to the side of a vessel that is outside its normal hull and which provides added deck space and/or greater flotation stability.





Indicates that an annular bacing has been made about a bolt hole to allow a nut or head to seat evenly.


Placing a container where required to be loaded or unloaded.


Beam or beam structure temporarily attached to and spanning the extremes of an item being lifted.

Spring line

Usually of the best wire hawsers; one of the first lines sent out in mooring. "Springs in and springs out" a vessel.


A steel or wooden post or pile that is placed vertically through a well in the hull of a vessel and which, when lowered to the bottom of the waterway, anchors the vessel.


A steel or wooden post or pile that is placed vertically through a well in the hull of a vessel and which, when lowered to the bottom of the waterway, anchors the vessel.


A casing which is attached to or passes through the hull of a vessel through which a spud is raised or lowered.


A casing which is attached to or passes through the hull of a vessel through which a spud is raised or lowered.


A sudden and violent gust of wind.

Square frame

A frame having no bevel on its flange. A midship frame


A deck dryer composed of a flat piece of wood shod with rubber, and a handle. Stanchions. Wooden or metal uprights used as supports (posts).


Signing and Releasing Bill of Lading


Single Rope Maximum Loading


Ship Security Alert System


Surface Supplied Breathing Apparatus


Saturdays, Sundays, Holidays Excluded


Saturdays, Sundays, Holidays Included


Ship Security Report System


Protruding hydraulically-activated fin(s) which reduces roll amplitude through oscillatory action creating alternating lift vectors phased to counter roll.




Tendency of the ship to remain upright.


It is paramount that a vessel is stable in all respects at all times. When cargo is loaded / discharged, the stability is monitored by a computer, which takes into account the weight and position of cargo within the vessel.


The ship's funnel or smokestack.


An articulated multiple platform rail car that allows containers to be double stacked.


A rail service whereby rail cars carry containers stacked two high on specially operated unit trains.


To zigzag a line, or row of rivet holes, etc.


Upright supports fastened together with horizontal and diagonal braces forming supports for planks which form a working platform.


An iron post or pillar for supporting the decks.


Stand by

A preparatory order

Standard compass

The magnetic compass used by the navigator as a standard.

Standing part

That part of a line or fall which is secured.

Standing rigging

That part of the ship's rigging which is permanently secured and not movable, such as stay, shrouds, etc.


Collars, forged of angle bars, to fit around continuous members passing through bulkheads or decks for watertightness.


The right side of a vessel looking forward.



A private room or cabin for the accommodation of passengers or officers.

Static load

Structural loading of constant magnitude and application.

Station bill

The posted bill showing stations of the crew at maneuvers and emergency drills.


Still, seaworthy, able.


A rope of hemp, wire or iron leading forward or aft for supporting a mast.


The rope, whether hemp or wire, that support the lower masts, topmasts, topgallant masts, etc., in a fore and aft direction.


Standards of Training, Certification and Watchkeeping


An order to hold a vessel on the course she is heading.

Stealer or steeler

The foremost or aftermost plate in a strake, which is dropped short of the stem or stern post of a vessel.

Steerage way

The slowest speed at which a vessel steers.

Steering flat

Compartment above the rudder(s) containing the vessel's steering actuation system(s).

Steering flat

Steering gear

A term applied to the steering wheels, leads, steering engine and fittings by which the rudder is turned.

Steering gear flat

The deck above the stern overhang, on which the rudder steering mechanism is installed.

Steering wheel

The wheel operating the steering gear and by which the vessel is steered.


The upright post or bar of the bow.


Stem foot

The forward end of the keel, into which the stem is fitted.

Stem the tide

Stemming the tide or sea means to head the vessel's bow directly into the current or waves. Overcome adverse circumstances.

Stepping-up pieces

Same as poppets.


The after part of the vessel.



Stern anchor

An anchor carried at the stern.

Stern board

Progress backwards.

Stern door

Watertight horizontally-hinged door integral to the transom on a stern-loading Ro-Ro vessel.

Stern frame

Large casting attached to after end of keel to form ship's stern. Includes rudder post, propeller post, and aperture for the propeller.

Stern pipe

A pipe leading to the opening at the side of poop deck for passing through of cables, chains, etc., for mooring purposes.

Stern post

The after post to which the rudder is hinged and placed on the skeg, with sufficient clearance for the propeller to revolve.

Stern ramp

Stern- (transom) mounted hinged platform located to permit the loading/discharge of vehicles aboard a Ro-Ro vessel.

Stern thruster

A propulsor installed near the stern to provide transverse a thrust component enhancing manoeuvrability.

Stern thruster

Stern tube

The bearing which supports the propeller shaft where it emerges from the ship. A cast iron or steel sylinder, fitted with brass bushings which are lined with lignum vitae or white metal bearing surfaces, upon which the propeller shaft, enclosed in a brass sleeve, rotates.

Stern tube


The reinforced, vertical shell plating which connects the stern rake bottom to the rake deck of a barge.


The reinforced, vertical shell plating which connects the stern rake bottom to the rake deck of a barge.


A professional cargo loader and unloader.


An angle bar or stringer fastened to a surface to strengthen it and make it rigid.



The Safe Transfer of Liquefied Gas in an Offshore Environment

Stop water

A wood plug driven through a scarf joint to stop water from leaking into the ship. The term is also applied to pieces of canvas soaked in oil, red lead, etc., placed between the faying surfaces of plates and shapes where water or oil is apt to work its way through.


A short length of rope secured at one end, and used in securing or checking a running rope, e.g., deck stopper, boat fall stopper, etc.


The space provided for stowage of provisions or other materials.

Storm warning

An announced warning of an approach of a storm.


A vessel with capacity for breakbulk cargo as well as vehicles or trailer borne cargo.


Broken in.


To put in place.

Stowage factor

The average cubic space occupied by one ton weight of cargo as stowed aboard a ship.


A person illegally aboard and in hiding.

Straddle carrier

Type of equipment that picks up and transports containers between its legs for movement within a container terminal.


A continuous line of plates on a vessel's side, reaching from stem to stern.


A number of yarns, twisted together and which in turn may be twisted into rope; a rope is stranded when a strain is broken; rope may be designated by the number of strands composing. Rope is commonly three-stranded. A vessel run ashore is said to be stranded.


A ring of rope made by splicing the ends, and used for slinging weights, holding the parts of a block together, etc. A rope, wire or iron binding, encircling a block and with a thimble seized into it for taking a hook. Small straps used to attach a handybilly to the hauling part of a line.

Streamlined rudder

A rudder with a bullnosed round forward edge which tapers regularly to a thin after edge.


A large beam or angle fitted in various parts of the vessel to give additional strength. Depending on their location, stringers are known as bilge stringers, side stringers, hold stringers, etc.

Stringer plate

A fore-and-aft member of deck plating which strengthens the connection between the beams and the frames, and keeps the beams square to the shell.

Strip theory

A simplified theory for calculating ship motions.

Stripping (unstuffing)

Unloading of a container.


A light spar set fore and aft on a boat, serving as a spread for the boat cover.


Support structure (with streamlined cross-section) for propeller shafting in a multi-screw vessel. [Alt shaft bracket.]


Ship to Ship


Standards of Training and Watchkeeping


Subject (to)


A term applied to cargo ships which are just able to transit the Suez Canal.


Person employed by a ship owner, shipping company, charterer of a ship or shipper of goods to supervise cargo handling operations. Often called a port captain.


(1) General term for sections of a vessel constructed on and above the upper or main decks of a vessel. (2) A more restrictive term under the International Convention on Load Lines, (1966) detached enclosed structure on the freeboard deck and extending transversely to within 4% of the breadth from the vessel's sides.



To ease a line to prevent it from parting or pulling, meanwhile holding the strain.


A mop.


Salt Water Arrival Draft


To bear or force down. An instrument having a groove on its under side for the purpose of giving shape to any piece subjected to it when receiving a blow from a hammer.


Sink by filling with water.

Swash bulkhead

A partial bulkhead used for the same purpose as a swash plate.

Swash bulkhead (plate)

Longitudinal or transverse perforated bulkhead (baffle) fitted in a tank to reduce the surging of the contents.

Swash bulkhead (plate)

Swash plates

Plates fixed in tanks to prevent excessive movement of the contained liquid.


Salt Water Departure Draft


A large wave.

Swing ship

The evolution of swinging a ship's head through several headings to obtain compass errors for the purpose of making a deviation table.

Swinging over

Swing of the boom from one side of the ship to the other when the tack is changed.


Safe working load; certified load limit applied to lifting appliances and gear.


Safe Working Load


A platform fitted with winches and anchor chain. The winches lower the platform into the water, the vessel is floated an and the platform is raised. Sometimes the vessel can be rolled to a repair station on railroad track.



Any combination of ropes and blocks that multiplies power. A single whip, improperly called tackle, gives no increase in power, but a change in direction of the power but a change in direction of the power applied.

Taffrail log

The log mounted on the taffrail and consisting of a rotator, a log line and recording device (to measure distance run through the water).


Aftermost section of the propeller shafting, carrying propeller.




Take a turn

To pass a turn around a belaying pin or cleat.

Take in

To lower and furl the sails.

Taking on more than you can carry

Loaded with more cargo than a ship can safely navigate with. Drunk.

Tank top

The plating laid on the bottom floors of a ship, which forms the top side of the tank sections or double bottom.


A ship designed to carry various types of liquid cargo, from oil and gasoline to molasses, water, and vegetable oil.


Compertments for liquids or gases. They may be formed by the ship's structure as double bottom tanks, peaktanks, deep tanks, etc., or may be independent of ship's structure and installed on special supports.

Tare weight

The weight of wrapping or packing; added to the net weight of cargo to determine.


Heavy canvas used as a covering.


With no slack; strict as to discipline.


Time to Closest Point of Approach

Tee bar

A rolled shape, generally of mild steel, having a cross section shaped like the letter "T". In ship work it is used for bulkhead stiffeners, bracket and floor clips, etc. The size is denoted by dimensions of its cross section and weight per running foot.


Means of signalling from bridge to engine room, etc.


A pattern made in themold loft from wood strips or heavy paper.


The end of a piece of wood cut into the form of a rectangular prism, designed to be set into a cavity of a like form in another piece which is termed mortise.

Test head

The head of water corresponding to the pressure prescribed as a test for bulkheads, tanks, compartments, etc. Test heads are prescribed to insure satisfactory water or oil tightness, and also as tests of strength.


Twenty-foot equivalent unit. A standard of measurement used in container transport based on the dimensions of a container 20 ft long ´ 8 ft wide ´ 8.5 ft high; (6050 ´ 2440 ´ 2590 mm).

That's high

An order to stop hoisting.


An iron ring with a groove on the outside for a rope grommet or splice.


The pins in the unwale of a boat which are used for carlocs.


The spiral part of a screw.

Three sheets to the wind

Sailing with three sheet ropes running free, thus making the ship barely able to keep headway and control. Drunk.

Throwing a Fish


Thrust block

A bearing arrangement, aft of the engine(s), by which the thrust of the propeller is transmitted to the ship.

Thrust block


The athwartships seats in a boat on which oars-men sit.


Boards extending across a rowboat just below the gunwale to stiffen the boat and to provide seats.


At right angles to the fore and aft line (across the ship).

Tie plates

A single fore-and-aft or diagonal course of plating attached to deck beans under wood deck to give extra strength.


An are attached to rudder head for operating the rudder.


Threshold Limit Value


Tonnage Measurement


Tanker Management Self Assessment


The edge of the flange of an angle.


A small piece of wood or bar of iron inserted in a knot to render it more secure, or to make it more readily unfastened or slipped.

Toggle pin

A pin, usually having an eye worked on the head, and having a point so constructed, that a portion of it it may turm on a pivot pin, forming a tee shaped looking device to keep the pin in place.


The tongue of a stern post or propeller post is the raised middle section which is fastened to the vertical keel. A a rule the tongue is raised twice as high as the sides of the dished keel.


A measure of the volume of a ship. In simple terms the gross tonnage (GRT)represents the total enclosed volume of the ship and the net tonnage (NT) represents the volume of cargo and passenger spaces. Tonnage is defined by internationally agreed formulae, and is used for dues for drydocking and pilotage and port and harbour dues etc. It should be noted that tonnage represents a function of volume and should not be confused with deadweight mass (tonnes), Lightship mass (tonnes) or displacement mass (tonnes).

Tonnage openings

Openings in shelter deck bulkheads for purpose of economy in tonnage rating.

Tonnage, gross

The entire internal cubic capacity of a vessel expressed in "tons" taken at 100 cubic feet each. The peculiarities of design and construction of the various tyoes of vessels and their parts necessitate certain explanatory rulings in connection with this term.

Tonnage, net

The internal cubic capacity of a vessel which remains after the capacities of certain specified spaces have been deducted from the gross tonnage.

Tonnes per centimetre immersion (TPC)

The extra buoyancy experienced due to increasing the draught by 1 cm.

Top breadth lines

The width of a vessel measured across the shelter deck.


Too heavy aloft.

Topping lift

A rope or chain extending from the head of a boom or gaff to a mast, or to the vessel's structure for the purpose of supporting the weight of the boom or gaff and its loads, and permitting them to be totated at a certain level.


That portion of the side of the hull which is above the desidgned water line.

Torsional strength

The strength of the hull in resisting twisting about a longitudinal axis.


To pull through water; vessels towed.


Charges for the services of tugs assisting a ship or other vessels in ports.


Third Party Auditor


Terminal Policy Review Group


Terminal Policy Steering Group


The path of the vessel.

Tractor propulsion

A system of vertical blades used to propel a vessel in the water. Used on some harbour tugs and ferries. Made by Volith. Sometimes called a cyclonic system in reference to the way the blades are mounted under the hull, and the way they turn.


The practically steady winds blowing toward the equator, N.E. in the northern and SE. in the southern hemisphere.

Tramp line

An ocean carrier company operating vessels on other than regular routes and schedules.


A distribution method whereby containers or cargo are transferred from one vessel to another to reach their final destination, compared to a direct service from the load port of origin to the discharge port of destination. This method is used to gain better vessel utilization and thereby economies of scale by consolidating cargo onto larger vessels while transiting in the direction of main trade routes.


Square-ended stern.



Transom beam

A strong deck beam in the after end of a vessel directly over the stern post, and connected at each end to the transom frame. The cant beams supporting the deck plating in the overhang of the stern radiate from it.

Transom frame or plate

A horizontal frame under a ship's counter.


(1) Alignment perpendicular to the centreplane of a vessel. (2) Deck beam.


Placed at right angles to the eel, such as a transverse frame, transverse bulkhead, etc. See also Abeam Athwart.

Transverse bulkhead

A partition wall of planking or plating running in an athwartship direction across a portion or the whole breadht of a ship. The principal function of transverse bulkheads is to divide the ship into a series of watertight compartments so that any rupture of the shell will not cause the loss of the vessel.

Transverse planes

Vertical planes normal to the centreline plane of the ship.

Transverse sections

The intersections of transverse planes with the envelope of the ship's hull.

Transverse stability

A measure of a ship's stability in relation to rotation about a longitudinal axis.


Fishing vessel designed for operation involving the towing of submerged nets.




Total Recorded Case Frequency


The length of a vessel's keel.


Wooden pins employed instead of nails or spikes to secure the planking of a wooden vessel to the frames.


To lash up.

Tricing line

A line used for suspending articles.


The period of time during which the wheelsman remains at the wheel.


The longitudinal attitude of a vessel, i.e., the difference between forward and aft drafts.


To let go.

Tripping brackets

Flat bars placed at various points on a deck girder or beams as reinforcement.

Tripping line

A line used for capsizing the sea anchor and hauling it in.


The flat circular piece secured on the top of the mast.


Vertical space or passage formed by bulkheads or casings extending 1 or more decks providing access or through which piping or cabling may be conducted.

Trunk bulkhead

The casing or partition that forms an enclosures running from deck to deck and surrounding the hatch openings.

Try square

A small and handy instrument for trying the square of surfaces while planing or fairing up with any tool. They come in various sezes and should be handled carefully to avoid knocking them out of true, and thus causing material to be spoiled by inaccurate work.


Training Ship Golden Bear (California Maritime Academy)


Traffic Separation Scheme




The after part of a ship where the sheel plating meets tn the run and is tucked together.


Small powerful and highly manoeuvrable vessel designed for towing, assisting and manoeuvring larger vessels in port or restricted waterways.



Tug boat

A small vessel fitted for towing.

Tumble home

Said of the sides of a vessel when thwy lean in at the top. When vertical they are called wallsided, when they lean out, flaring.


Turn in all standing

Go to bed without undressing.

Turn to

An order to commence ship's work.

Turn turtle

To capsize.

Turnaround time

The time it takes between the arrival of a vessel and it's departure from port; frequently used as a measure of port efficiency.


A connecting device usually used with cable or chain and which takes up slack by rotating on its screw threads. back




Used to pull objects together. A link threaded on both ends of a short bar, one left handed, the other right handed.


Structures designed for the mounting and handling of the guns and accessories (usually main battery guns) of a war vessel. Turrents are constructed so as to revolve about a vertical axis usually by means of electrical or hydraulic machinery.


Tween Decker

Tween decks

The space between any continuous decks.


Intermediate deck within a cargo space above the lower hold and below the upper deck.


Twenty-foot equivalent unit (TEU)

Container size standard of twenty feet. Two twenty-foot containers (TEUs) equal one FEU. Container vessel capacity and port throughput capacity are frequently referred to in TEUs.

Two blocks

When the two blocks of a tackle have been drawn as close together as possible.



United Kingdom Hydrographic Office (provides AIO)


Ultra large crude carrier. Tanker of deadweight greater than 320,000 tonnes.



Ullage hatch

A small hinged opening on a tank for gauging or sampling cargo. The ullage is the distance from the top of this hatch to the top of the cargo. It is the "opposite" of innage.

Ullage opening

A small, covered opening in the top of a cargo tank through which measurements are made to determine the level of the liquid in the tank.


A metal shield in the form of a trustrum of qa cone, fitted to the outer casing of the smokestack over the air casing to keep out the weather.


To untie.

Under below

A warning from aloft (heads up).


Insufficient number of crew; shorthanded.


A subsurface current in a surf.


Said of a vessel when not at anchor, nor made fast to the shore, or aground.


The consolidation of a quantity of individual items into one large shipping unit for easier and faster handling through methods such as palletizing, stripping, slinging and containerization.


Port equipment employed to unload ships carrying dry bulk cargo.


To remove the ropes that attach a ship to the shore.


To remove anything from its usual place. To take apart.

Unstuffing (or stripping)

Unloading of a container.


Said of a lighthouse not tended.

Up anchor

Hoist or haul in the anchor.

Upper deck

A partial deck above the main deck amidships.

Upper works

Superstructures, or deck erections located on or above the weather deck. Sometimes used with reference to a ship's entire above-water structure.


A sheet metal conduit connecting the boiler furnace with thw base of the smokestack. It conveys the smoke and hot gases from the boiler to the stack, and should be made double thickness with an air space between to prevent radiation. Swinging dampers for controlling the fires are fitted in the uptake.


Unless Sooner Commenced


Uniform Shipping Laws (Australian federal code for the design, construction and stability of vessels.)


Unless Used


Unless Used If Used Actual Time Used To Count


Vapor Header

A pipeline connected to the top of a cargo tank that channels the displaced tank vapors to a shoreside control system.


An order to cease (stop).


Vertical center of gravity; an important computation used in the determination of the stability of a vessel with its cargo. back


Vertical center of gravity; an important computation used in the determination of the stability of a vessel with its cargo. back


To slack off or move off; also said of a change of direction of wind, when the wind shifts to a different direction.


Vessel Experience Factor




The process of providing fresh air to the various spaced, and removing foul or heated air, gases, etc., from them. This may be accomplished by natural sraft or by mechanical means.

Ventilations, bell-mouthed or cowl

Terminals on open decks in the form of a 90o elbow with enlarged or bell shaped openings, so formed as to obtain an increase of air supply when facing the wind and to increase the velocity of air down the ventilation pipe.


Installation or nacelle for the intake or exhaust of ventilation air for enclosed spaces.

Ventilator cowl

The swiveled opening at the top of a ventilator.

Vertical keel

A plate running in a fore and aft direction connecting to the flat keel and keel rider plates, it is usually connected by two angles at the top and bottom for a riveted job or welded to the keel and keel rider.

Vessel manifest

Declarations made by international ocean carriers relating to the ship's crew and contents at both the port of departure and arrival. All bills af lading are registered on the manifest.

Vessel traffic management system

Vessel control and management system (VTMS) usually under the authority of the harbormaster, comprising equipment (such as radars, tracking software, and radio communications), personnel (traffic operators0, and regulations. Most larger maritime ports have relatively advanced vessel traffic management systems for maritime safety, protection of the enviroment, and coordination of marine services.


Very High Frequency


Vessel Inspection Questionnaire


A small inclined awning running around the pilot house over the windows or air ports to exclude the glare of the sun or to prevent rain or spray from coming in the openings when the glazed frames are dropped or opened. They may be of canvas or metal.


Very large crude carrier. Tanker of deadweight between 160,000 and 320,000 tonnes.


Very Large Ore Carrier


Volatile Organic Compound

Voice tube

A tube designed for the carriage of the human voice from one part of the ship to another. In its simplest form the voice tube system includes a speaking connection between the pilot house and engine room only. In large war vessels the system becomes very complicated. Voice tubes are generally made up to about four inchesin diameter and fitted with appropriate speaking and listening terminals.

Void space

Enclosed space (often watertight) intentionally left empty; (e.g., cofferdam).

Void tank

A watertight space that does not carry ballast or cargo. For floatation.


Voyage Plan


Vessel Protection Detachment


Vessel Pays Dues


Vessel Particulars Questionnaire


Variable Range Marker


Vessel Tracking System



The portion of the deck between the forecastle and quarterdeck of a sailing vessel.


The disturbed water left behind by a moving ship.


See Harpings.


A room or space on shipboard set aside for use of the officers for social purpose and also used as their mess or dining room.


Weather Analysis Service Provider


Cotton yarn used for cleaning purposes.

Watch cap

A canvas cover secured over a funnel when not in use. Sailor's headwear, woolen type, capable of covering the ears in cold weather.

Watch officer

An officer taking his turn as officer of the watch.

Water breaker

A small cask carried in ship's boats for drinking purposes.

Water lines

Lines drawn parallel with the surface of the water at varing heights on a ship's outline. In the sheer plan they are straight and horizontal, in the half-breadth plan they show the form of the ship at each of the successive heights marked.


The line painted on the side of the vessel at the water's edge to indicate the proper trim.


A ship full of water but still afloat.


Filled with water but afloat.

Water's edge

The surface of the water.


Capable of preventing the ingress of water under a head of water likely to occur in the intact or damaged condition.

Watertight bulkhead

A partition of plating reinforced where necessary with stiffering bars and capable of preventing the flow of water under pressure from one compartment to another.

Watertight compartment

A space or compartment whithin a ship having its top, bottom, ans sides constructed in such a manner as to prevent the leakage of water into or from the space.

Watertight door

A door so constructed that, when closed, it will prevent water under pressure from passing throught.


A gutter-like recess on the shelter deck at the midship section of a ship, which delivers excess water the sea.

Waterway bar

An angle or flat bar attached to a deck stringer plate forming the in-board boundary of a waterway and serving as an abutment for the wood deck plating.


Document, issued by a shipping line to a shipper, which serves as a receipt for the goods and evidence of the contract carrier.


The timber sills upon which a ship is built.


Whether Customs Cleared Or Not


Wind and Current Drag Coefficient Task Group

Weather deck

Uppermost hull deck exposed to the weather at all times.

Weather deck

Weather eye

To keep a weather eye is to be on the alert (heads up).

Weather side

The windward side (from where the wind is blowing).


Capable of preventing the ingress of water in any wind and wave conditions up to those specified as critical design conditions.


The vertical portion of a beam, the athwartship portion of a frame.

Web frame

Transverse side frame with deeper web, spaced at multiples of main frame stations for the provision of extra strength.

Web frame


The very slow issuance of water through the seamsof a ship's structure or from a containing vessel in insufficient quantity to produce a stream.


Lift anchor off the bottom.

Weigh anchor

To lift anchor off the sea bottom.


The method of fastening steel objects together by fusing the metal with a gas flame or an electrical arc.

Welding bead

A seam made by closing a joint with molten metal applied with a welding stick.


The space between the first bulkhead of a long poop deck or deck house and a fore-castle bulkhead.

Well deck

A sunken deck on a marchant vessel, fitted between the forecastle and a long poop or continuous bridge house or raised quarter deck.

Well enough

An order meaning sufficient (enough).


World Geodetic System 1984


Any steel or wooden member used for temporarily bracing a bulkhead, deck section, etc.


Structure built alongside the water or perpendicular to the shore where ships berth for loading or discharging goods.


The charge that an owner of a facility charges for the movement of cargo through that facility.


Nickname for propeller, steering gear control.

Where away

A call requesting direction in answer to the report of a lookout that an object has been sighted.


A method of preventing the ends of a line from unlaying or fraying by turns of small stuff, stout twine or seizing wire with the ends tucked.

White cap

The white froth on the crests of waves.


Whether In Berth Or Not

Wide berth

At a considerable distance.


Whether In Free Pratique or not


A sprocket wheel on the windlass for taking links of the chain cable.


A hoisting or pulling machine fitted with a horizontali single or double srum. A small drum is generally fitted on one or both ends of the shaft supporting the hoisting drum. These small drums are called gypsides, niggerheads, or winch heads. The hoisting drums either are fitted with a friction brake or are directly keyed to the shaft. The driving power is usually steam or electricity but hand power is also used. A winch is used principally for the purpose of handling, hoisting, and lowering cargo from a dock or lighter to the hold of a ship and vice versa.


Wind scoop

A device used to divert air into a compartment of a ship.


An apparatus in which horizontallor vertical drums or gypsides and wildcats are operated by means of a steam engine or motor for the purpose of handling heavy anchor chair hawsers, etc.



To overhanging part of a deck on a ferry boat, or fore and aft of paddle boxes in a side wheeler. Also used to indicate outboard parts of the ship, such as in the wings of the hold.

Wing brackets

The arge brackets which fasten the margin plates to the lower frame ends. (Also known as deep bracket knees and bilge brackets).

Wing passage

A passage way below the water line on a man-of-war, used for repairs and inspections.

Wing tank

Ballast or cargo tank adjacent to the hull side.

Wing tank

Wing tanks

Tanks located autboard and usually just under the wether deck. They are sometimes formed by fitting a longitudinal bulkhead between the two uppermost decks, ans sometimes by working a diagonal, longitudinal flat between the ship's side and the weather deck.


A general handyman in the engine room.


Whether In Port Or Not

Wire mesh bulkhead

A partition built up of wire mesh panel.


(distance) Water Line-To-Hatch Coaming


Without Guarantee


Weather Permitting Day


Wire Rods In Coils


Western Terminal Forum


Weather Working Day


When, Where Ready


Wibon, Wccon, Wifpon, Wipon



Private or charter vessel designed for pleasure cruising, racing, etc. propelled by wind or power.




York Antwerp Rules


A term applied to a spar attached at its middle portion to a mast and running athwartship across a vessel as a support for a square sail. Signal halyards, lights, etc.


A term applied to the outer end if a yard.


To steer wildly or out of line of course.

Yield stress

Stress limit within a material at which plastic (permanent) strain commences under load.



Propulsion train configuration where the engine output and propeller shafts are horizontal and parallel and linked via an intermediate vertical shaft.





A structural shape with a cross section resembling the letter Z.


When the sun is in the zenith and observed with a sextant, the arc will be 90o from the horizon.

Zinc primer

Common corrosion inhibiting primer used to coat bare steel prior to subsequent paint coatings being applied.

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