Glossary of Nautical Terms

                                                         Glossary of Nautical Terms

A
Above board – On or above the deck, in plain view, not hiding anything.
Act of Pardon / Act of Grace – A letter from a state or power authorising action by a privateer. Also see Letter of Marque.
Abaft – Toward the stern, relative to some object ("abaft the fore hatch")
Abaft the beam – A relative bearing of greater than 90 degrees from the bow. e.g. "two points abaft the port beam."
Abandon Ship – An imperative to leave the vessel immediately, usually in the face of some imminent danger.
Abeam – 'On the beam', a relative bearing at right angles to the centerline of the ship's keel.
Abel Brown – A sea song (shanty) about a young sailor trying to sleep with a maiden. [1].
Aboard – On or in a vessel. Close aboard means near a ship.
Absentee pennant – Special pennant flown to indicate absence of commanding officer, admiral, his chief of staff, or officer whose flag is flying (division, squadron, or flotilla commander).
Accommodation ladder – A portable flight of steps down a ship's side.
Admiralty – A high naval authority in charge of a state's Navy or a major territorial component. In the Royal Navy (UK) the Board of Admiralty, executing the office of the Lord High Admiral, promulgates Naval law in the form of Queen's (or King's) Regulations and Admiralty Instructions.
Admiralty law – Body of law that deals with maritime cases. In UK administered by the Probate, Divorce and Admiralty Division of the High Court of Justice.
Adrift – Afloat and unattached in any way to the shore or seabed. It may also imply that a vessel is not anchored and not under control, therefore goes where the wind and current take her, (Loose from moorings, or out of place).
Advance note – A note for one month's wages issued to sailors on their signing a ship's articles.
Aft – Towards the stern (of the vessel)
Afternoon watch – The 1200-1600 watch.
Aground – Resting on or touching the ground or bottom.
Ahead – Forward of the bow.
Ahoy – A cry to draw attention. Term used to hail a boat or a ship, as "Boat ahoy!"
Aid to Navigation – (ATON) Any device external to a vessel or aircraft specifically intended to assist navigators in determining their position or safe course, or to warn them of dangers or obstructions to navigation.
All hands – Entire ship's company, both officers and enlisted personnel.
All night in – Having no night watches.
Aloft – Above the ship's uppermost solid structure; overhead or high above.
Alongside – By the side of a ship or pier.
Amidships (or midships) – In the middle portion of ship, along the line of the keel.
Anchor – An object designed to prevent or slow the drift of a ship, attached to the ship by a line or chain; typically a metal, hook like, object designed to grip the bottom under the body of water.
Anchorage – A suitable place for a ship to anchor. Area of a port or harbor.
Anchor's aweigh – Said of an anchor when just clear of the bottom.
Anchor ball – Black shape hoisted in forepart of a ship to show that ship is anchored in a fairway.
Anchor buoy – A small buoy secured by a light line to anchor to indicate position of anchor on bottom.
Anchor chain or cable – Chain connecting the ship to the anchor.
Anchor detail – Group of men who handle ground tackle when the ship is anchoring or getting underway.
Anchor light – White light displayed by a ship at anchor. Two such lights are displayed by a ship over 150 feet in length.
Anchor watch – Making sure that the anchor is holding and the vessel is not drifting. Important during rough weather and at night. Most marine GPS units have an Anchor Watch alarm capability.
Arc of Visibility – The portion of the horizon over which a lighted aid to navigation is visible from seaward.
Armament – A ship's weapons.
Articles of War – Regulations governing the military and naval forces of UK and USA; read to every ship's company on commissioning and at specified intervals during the commission.
Ashore – On the beach, shore or land.
Astern – Toward the stern; an object or vessel that is abaft another vessel or object.
ASW – Anti-submarine warfare.
Athwart, athwartships – At right angles to the fore and aft or centerline of a ship
Avast – Stop! Cease or desist from whatever is being done.
Awash – So low in the water that the water is constantly washing across the surface.
Aweigh – Position of an anchor just clear of the bottom.
Aye, aye – Reply to an order or command to indicate that it first heard, and second is understood and will be carried out. ("Aye, aye, sir" to officers)
Azimuth compass – An instrument employed for ascertaining position of the sun with respect to magnetic north. The azimuth of an object is its bearing from the observer measured as an angle clockwise from true north.
Azimuth circle – Instrument used to take bearings of celestial objects.

B
Back and fill – To use the advantage of the tide being with you when the wind is not.
Backstays – Long lines or cables, reaching from the rear of the vessel to the mast heads, used to support the mast.
Baggywrinkle – A soft covering for cables (or any other obstructions) that prevents sail chafing from occurring.
Bank (sea floor) – A large area of elevated sea floor
Bar – Large mass of sand or earth, formed by the surge of the sea. They are mostly found at the entrances of great rivers or havens, and often render navigation extremely dangerous, but confer tranquility once inside. See also: Touch and go, grounding. Alfred Lord Tennyson's poem 'Crossing the bar' an allegory for death.
Barrelman – A sailor that was stationed in the crow's nest.
Bar pilot – A bar pilot guides ships over the dangerous sandbars at the mouth of rivers and bays.
Beacon – A lighted or unlighted fixed aid to navigation attached directly to the earth’s surface. (Lights and daybeacons both constitute beacons.)
Beam – The beam of a ship is its width at the widest point, or a point alongside the ship at the mid-point of its length.
Beam ends– The sides of a ship. "On her beam ends" may mean the vessel is literally on her side and possibly about to capsize; more often, the phrase means the vessel is listing 45 degrees or more.
Bear – Large squared off stone used for scraping clean the deck of a sailing man-of-war.
Bear down – Turn away from the wind, often with reference to a transit.
Bearing – The horizontal direction of a line of sight between two objects on the surface of the earth.
Before the mast – Literally, the area of a ship before the foremast (the forecastle). Most often used to describe men whose living quarters are located here, officers being housed behind (abaft) the mast and enlisted men before the mast. This was because the midships area where the officers were berthed is more stable, being closer to the center of gravity, and thus more comfortable. It is less subject to the up and down movement resulting from the ship's pitching.
Belaying pins – Bars of iron or hard wood to which running rigging may be secured, or belayed.
Berth – A bed on a boat, or a space in a port or harbour where a vessel can be tied up.
Between the Devil and the deep blue sea – See Devil seam.
Bilge – The bilge is the compartment at the bottom of the hull of a ship or boat where water collects so that it may be pumped out of the vessel at a later time.
Bilged on her anchor – A ship that has run upon her own anchor.
Bimini – Weather-resistant fabric stretched over a stainless steel frame, fastened above the cockpit of a sailboat or flybridge of a power yacht which serves as a rain or sun shade.
Bimmy – A punitive instrument
Binnacle – The stand on which the ship's compass is mounted.
Binnacle list – A ship's sick list. The list of men unable to report for duty was given to the officer or mate of the watch by the ship's surgeon. The list was kept at the binnacle.
Bitt, plural Bitts – Posts mounted on the ship's bow, merely comprising two wooden uprights supporting a crossbar, for fastening ropes or cables; also used on various ships to tie boys over for painful (posterior) discipline, more informally than kissing the gunner's daughter.
Bitter end – The anchor cable is tied to the bitts, when the cable is fully paid out, the bitter end has been reached. The last part of a rope or cable.
Bloody – An intensive derived from the substantive 'blood', a name applied to the Bucks, Scrowers, and Mohocks of the seventeenth centuries.
Blue Peter – A blue and white flag hoisted at the foretrucks of ships about to sail.
Boat – A craft or vessel designed to float on, and provide transport over, water.
Boatswain or bosun – A non-commissioned officer responsible for the sails, ropes and boats on a ship who issues "piped" commands to seamen.
Bollard – From 'bol' or 'bole', the round trunk of a tree. A substantial vertical pillar to which lines may be made fast. Generally on the quayside rather than the ship.
Bombay runner – Large cockroach.
Bonded Jacky – A type of tobacco or sweet cake.
Booby – A type of bird that has little fear and therefore is particularly easy to catch, hence booby prize.
Booby hatch – A sliding hatch or cover.
Boom – A spar used to extend the foot of a sail.
Booms – Masts or yards, lying on board in reserve.
Boom vang (vang) – A sail control that lets one apply downward tension on the boom, countering the upward tension provided by the mainsail. The boom vang adds an element of control to mainsail shape when the mainsheet is let out enough that it no longer pulls the boom down. Boom vang tension helps control leech twist, a primary component of sail power.
Buoy – A floating object of defined shape and color, which is anchored at a given position and serves as an aid to navigation.
Bow – The front of a ship.
Bow-chaser, chase or chase-piece – A long gun with a relatively small bore, placed in the bow-port to fire directly ahead. Used especially while chasing an enemy vessel to damage its sails and rigging. (quoted from A Sea of Words)
Bowline – A type of knot, producing a strong loop of a fixed size, topologically similar to a sheet bend. Also a rope attached to the side of a sail to pull it towards the bow (for keeping the windward edge of the sail steady).
Bowse – To pull or hoist.
Bowsprit – A spar projecting from the bow used as an anchor for the forestay and other rigging.
Boy seaman – a young sailor, still in training
Brail – To furl or truss a sail by pulling it in towards the mast, or the ropes used to do so.
Brake – The handle of the pump, by which it is worked.
Brass monkeys or brass monkey weather – Very cold weather, origin unknown. A widely circulated folk etymology claiming to explain what a brass monkey is has been discredited by several people including Snopes [2] and the Oxford English Dictionary.
Bridge – A structure above the weather deck, extending the full width of the vessel, which houses a command centre, itself called by association, the bridge.
Bring to – Cause a ship to be stationary by arranging the sails.
Broaching-to – A sudden movement in navigation, when the ship, while scudding before the wind, accidentally turns her leeward side to windward, also use to describe the point when water starts to come over the gunwhale due to this turn.
Buffer – The chief bosun's mate (in the Royal Navy), responsible for discipline.
Bulkhead – An upright wall within the hull of a ship. Particularly a load bearing wall.
Bull of Barney – A beast mentioned in an obscene sea proverb.
Bulwark – The extension of the ship's side above the level of the weather deck.
Bumboat – A private boat selling goods.
Bumpkin – An iron bar (projecting out-board from a ship's side) to which the lower and topsail brace blocks are sometimes hooked. Chains supporting/stabilising the bowsprit.
Buntline – One of the lines tied to the bottom of a square sail and used to haul it up to the yard when furling.
Bunting Tosser – A signalman who prepares and flies flag hoists.
Buoyed Up – Lifted by a buoy, especially a cable that has been lifted to prevent it from trailing on the bottom.
By and Large – By means into the wind, while large means with the wind. By and large is used to indicate all possible situations "the ship handles well both by and large".
By the board – Anything that has gone overboard.

C
Cabin – an enclosed room on a deck or flat.
Cabin boy – attendant on passengers and crew.
Cable – A large rope; also a measure of length or distance. Equivalent to (UK) 1/10 nautical mile, approx. 600 feet; (USA) 120 fathoms, 720 feet (219 m); other countries use different values.
Canister – a type of anti personnel cannon load in which lead balls or other loose metallic items were enclosed in a tin or iron shell. On firing the shell would disintegrate releasing the smaller metal objects.
Cape Horn fever – The name of the fake illness a malingerer is pretending to suffer from.
Capsize – When a ship or boat lists too far and rolls over, exposing the keel. On large vessels, this often results in the sinking of the ship.
Capstan – A rotating wheel mounted vertically, used to wind in anchors or other heavy objects; and sometimes to administer flogging over.
Captain's daughter – The cat o' nine tails, which in principle is only used on board on the captain's (or a court martial's) personal orders.
Careening – Cause the ship to tilt on its side, usually to clean or repair the hull below the water line.
Cat – 1. To prepare an anchor, after raising it by lifting it with a tackle to the Cat Head, prior to securing (fishing) it alongside for sea. (An anchor raised to the Cat Head is said to be catted). 2. The Cat o' Nine Tails (see below). 3. A cat-rigged boat or catboat.
Catamaran – A vessel with two hulls.
Catboat – A cat-rigged vessel with only one sail, usually on a gaff.
Cat o' nine tails – A short nine-tailed whip kept by the bosun's mate to flog sailors (and soldiers in the Army).
Cat Head – A beam extending out from the hull used to support an anchor when raised in order to secure or 'fish' it.
Centreboard – A removable keel used to resist leeway.
Chafing – Wear on line or sail caused by constant rubbing against another surface.
Chafing Gear – Material applied to a line or spar to prevent or reduce chafing. See Baggywrinkle.
Chain shot – Cannon balls linked with chain used to damage rigging and masts.
Chain-wale or channel – A broad, thick plank that projects horizontally from each of a ship's sides abreast a mast, distinguished as the fore, main, or mizzen channel accordingly, serving to extend the base for the shrouds, which supports the mast.
Chase guns – Cannons mounted on the bow or stern. Those on the bow could be used to fire upon a ship ahead, while those on the rear could be used to ward off pursuing vessels.
Chine – A relatively sharp angle in the hull, as compared to the rounded bottoms of most traditional boat hulls.
Chock-a-block – Rigging blocks that are so tight against one another that they cannot be further tightened.
Clean bill of health – A certificate issued by a port indicating that the ship carries no infectious diseases.
Clean slate – At the helm, the watch keeper would record details of speed, distances, headings, etc. on a slate. At the beginning of a new watch the slate would be wiped clean.
Cleat – A stationary device used to secure a rope aboard a vessel.
Clew-lines – Used to truss up the clews, the lower corners of square sails.
Club hauling The ship drops one of its anchors at high speed to turn abruptly. This was sometimes used as a means to get a good firing angle on a pursuing vessel.
Coaming – The raised edge of a hatchway used to help keep out water.
Compass – Navigational instrument that revolutionised travel.
Corrector – a device to correct the ship's compass.
Courses – The mainsail, foresail, and the mizzen.
Coxswain or cockswain – The helmsman or crew member in command of a boat.
As the crow flies – A direct line between two points (which might cross land) which is the way crows travel rather than ships which must go around land.
Crow's nest – Specifically a masthead constructed with sides and sometimes a roof to shelter the lookouts from the weather, generally by whaling vessels, this term has become a generic term for what is properly called masthead. See masthead.
Cuddy – A small cabin in a boat.
Cunningham – A line invented by Briggs Cunningham, used to control the shape of a sail.
Cunt splice – A join between two lines, similar to an eye-splice, where each rope end is joined to the other a short distance along, making an opening which closes under tension.
Cuntline – The "valley" between the strands of a rope or cable. Before serving a section of laid rope e.g. to protect it from chafing, it may be "wormed" by laying yarns in the cuntlines, giving that section an even cylindrical shape.
Cut and run – When wanting to make a quick escape, a ship might cut lashings to sails or cables for anchors, causing damage to the rigging, or losing an anchor, but shortening the time needed to make ready by bypassing the proper procedures.
Cut of his jib – The "cut" of a sail refers to its shape. Since this would vary between ships, it could be used both to identify a familiar vessel at a distance, and to judge the possible sailing qualities of an unknown one.

D
Daggerboard – A type of centerboard that is removed vertically.
Davy Jones’ Locker – An idiom for the bottom of the sea
Daybeacon – An unlighted fixed structure which is equipped with a dayboard for daytime identification.
Dayboard – The daytime identifier of an aid to navigation presenting one of several standard shapes (square, triangle, rectangle) and colors (red, green, white, orange, yellow, or black).
Decks – the structures forming the approximately horizontal surfaces in the ship's general structure. Unlike flats, they are a structural part of the ship.
Deck hand – A person whose job involves aiding the deck supervisor in (un)mooring, anchoring, maintenance, and general evolutions on deck.
Deck supervisor – The person in charge of all evolutions and maintenance on deck; sometimes split into two groups: forward deck supervisor, aft deck supervisor.
Deckhead – The under-side of the deck above. Sometimes panelled over to hide the pipe work. This panelling, like that lining the bottom and sides of the holds, is the ceiling.
Deadeye – A round wooden plank which serves a similar purpose to a block in the standing rigging of large sailing vessels.
Deadrise – The design angle between the keel (q.v.) and horizontal.
Derrick – A lifting device composed of one mast or pole and a boom or jib which is hinged freely at the bottom.
Devil seam – The curved seam in the hull planking closest to the waterline when the ship is level. The seam between these two planks, set at a nominal right angle to each other, is the devil seam. This seam is particularly difficult to pay (and caulk) because there is little support in the direction of the compression created during caulking and expansion of the wood when wet. Hence, this seam "works" a lot. A sailor sealing this seam must first cause the ship to list (lean) toward the side opposite of the seam. This allows the salior access to the seam by hanging below it, "between the Devil and the deep blue sea".
Devil to pay (or Devil to pay, and no pitch hot) – 'Paying' the Devil is sealing the devil seam. It is a difficult and unpleasant job (with no resources) because of the shape of the seam (closest to the waterline) and because you are positioned below the natural waterline.
Directional Light – A light illuminating a sector or very narrow angle and intended to mark a direction to be followed.
Dog watch – A short watch period, generally half the usual time (eg a two hour watch between two four hour ones). Such a watch might be included in order to slowly rotate the system over several days for fairness, or to allow both watches to eat their meals at approximately normal times.
Dolphin – A structure consisting of a number of piles driven into the seabed or riverbed in a circular pattern and drawn together with wire rope.
Downhaul – A line used to control either a mobile spar, or the shape of a sail.
Draft – The depth of a ship's keel below the waterline.
Draught – See draft.
Dressing down – Treating old sails with oil or wax to renew them, or a verbal reprimand.
Driver – The large sail flown from the mizzen gaff.
Dunnage – Loose packing material used to protect a ship's cargo from damage during transport. Personal baggage.

E
Earrings – Small lines, by which the uppermost corners of the largest sails are secured to the yardarms.
Embayed – The condition where a sailing vessel is confined between two capes or headlands, typically where the wind is blowing directly onshore.
Extremis – (also known as “in extremis”) the point under International Rules of the Road (Navigation Rules) at which the privileged (or stand-on) vessel on collision course with a burdened (or give-way) vessel determines it must maneuver to avoid a collision. Prior to extremis, the privileged vessel must maintain course and speed and the burdened vessel must maneuver to avoid collision.

F
Fathom – A unit of length equal to 6 feet, roughly measured as the distance between a man's outstretched hands.
Fender – An air or foam filled bumper used in boating to keep boats from banging into docks or each other.
Figurehead – symbolic image at the head of a traditional sailing ship or early steamer.
Fireship – A ship loaded with flammable materials and explosives and sailed into an enemy port or fleet either already burning or ready to be set alight by its crew (who would then abandon it) in order to collide with and set fire to enemy ships.
First rate – The classification for the largest sailing warships of the 17th through 19th centuries. They had 3 masts, 850+ crew and 100+ guns.
Fish – 1. To repair a mast or spar with a fillet of wood. 2. To secure an anchor on the side of the ship for sea (otherwise known as "catting".)
First Lieutenant – In the Royal Navy, the senior lieutenant on board; responsible to the Commander for the domestic affairs of the ship's company. Also known as 'Jimmy the One' or 'Number One'. Removes his cap when visiting the mess decks as token of respect for the privacy of the crew in those quarters. Officer i/c cables on the forecastle. In the U.S. Navy the senior person in charge of all Deck hands.
First Mate – The Second in command of a ship
Flag hoist – A number of signal flags strung together to convey a message, e.g. 'England expects...'.
Flank – The maximum speed of a ship. Faster than "full speed".
Flatback – A Great Lakes slang term for a vessel without any self unloading equipment.
Fluke – The wedge-shaped part of an anchor's arms that digs into the bottom.
Fly by night – A large sail used only for sailing downwind, requiring little attention.
Following sea – Wave or tidal movement going in the same direction as a ship
Foot – The bottom of a sail.
Footloose – If the foot of a sail is not secured properly, it is footloose, blowing around in the wind.
Footrope – Each yard on a square rigged sailing ship is equipped with a footrope for sailors to stand on while setting or stowing the sails
Forecastle – A partial deck, above the upper deck and at the head of the vessel; traditionally the sailors' living quarters.
Founder – To fill with water and sink ? Wiktionary
Fore – Towards the bow (of the vessel).
Foremast jack – An enlisted sailor, one who is housed before the foremast.
Forestays – Long lines or cables, reaching from the front of the vessel to the mast heads, used to support the mast.
Freeboard – The height of a ship's hull (excluding superstructure) above the waterline. The vertical distance from the current waterline to the lowest point on the highest continuous watertight deck. This usually varies from one part to another.
Full and by – Sailing into the wind (by), but not as close-hauled as might be possible, so as to make sure the sails are kept full. This provides a margin for error to avoid being taken aback (a serious risk for square-rigged vessels) in a tricky sea. Figuratively it implies getting on with the job but in a steady, relaxed way, without undue urgency or strain.
Furl – To roll or wrap a sail around the mast or spar to which it is attached.

G
Gaff – The spar that holds the upper edge of a sail. Also a long hook with a sharp point to haul fish in.
Galley – the kitchen of the ship
Gangplank – a movable bridge used in boarding or leaving a ship at a pier; also known as a "brow".
Garbled – Garbling was the (illegal) practice of mixing cargo with garbage.
Garboard – The strake closest to the keel (from Dutch gaarboard).
Global Positioning System – (GPS) A satellite based radionavigation system providing continuous worldwide coverage. It provides navigation, position, and timing information to air, marine, and land users.
Grapeshot – Small balls of lead fired from a cannon, similar to shotgun shot on a larger scale. Used to hurt people, rather than cause structural damage.
Grog – Watered-down pusser's rum consisting of half a gill with equal part of water, issued to all seamen over twenty. (CPOs and POs were issued with neat rum) From the British Admiral Vernon who, in 1740, ordered the men's ration of rum to be watered down. He was called "Old Grogram" because he often wore a grogram coat), and the watered rum came to be called 'grog'. Often used (illegally) as currency in exchange for favours in quantities prescribed as 'sippers' and 'gulpers'. Additional issues of grog were made on the command 'splice the mainbrace' for celebrations or as a reward for performing especially onerous duties. The RN discontinued the practice of issuing rum in 1970.
Groggy – Drunk from having consumed a lot of grog.
Gunner's daughter – see Kissing the G.'s D.
Gunwale – Upper edge of the hull.