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 stern 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.
Bailer: A device for removing water that has entered the boat.
Ballast Tank: A device used on ships and submarines and other submersibles to control buoyancy and stability
Balls to four watch: The 0000–0400 watch. (US Navy)
Bank: A large area of elevated sea floor.
Banyan: Traditional Royal Navy term for a day or shorter period of rest and relaxation.
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" is an allegory for death.
Bar pilot: A bar pilot guides ships over the dangerous sandbars at the mouth of rivers and bays.
Barrelman: A sailor that was stationed in the crow's nest.
1. A stiff strip used to support the roach of a sail, enabling increased sail area
2. Any thin strip of material (wood, plastic etc) which can be used any number of ways
Batten down the hatches: To prepare for inclement weather by securing the closed hatch covers with wooden battens so as to prevent water from entering from any angle.
Beaching: Deliberately running a vessel aground to load and unload (as with landing craft), or sometimes to prevent a damaged vessel sinking.
Beacon: A lighted or unlighted fixed aid to navigation attached directly to the earth’s surface. (Lights and daybeacons both constitute beacons.)
Beam: The width of a vessel 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 with sand for scraping clean wooden decks.
Bear down or bear away: 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. See also "absolute bearing" and "relative bearing".
Beating or Beat to: Sailing as close as possible towards the wind (perhaps only about 60°) in a zig-zag course to attain an upwind direction to which it is impossible to sail directly.(also tacking)
Beat to quarters: Prepare for battle (beat = beat the drum to signal the need for battle preparation)
Beaufort scale: The scale describing wind force devised by Admiral Sir Francis Beaufort in 1808, in which winds are graded by the effect of their force (originally, the amount of sail that a fully rigged frigate could carry). Scale now reads up to Force 17.
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 quartered in the stern-most areas of the ship (near the quarterdeck). Officer-trainees lived between the two ends of the ship and become known as "midshipmen". Crew members who started out as seamen, then became midshipmen, and later, officers, were said to have gone from "one end of the ship to the other" (also see hawsepiper).
1. To make fast a line around a fitting, usually a cleat or belaying pin.
2. To secure a climbing person in a similar manner.
3. An order to halt a current activity or countermand an order prior to execution.
Belaying pins: Short movable bars of iron or hard wood to which running rigging may be secured, or belayed.
Bend: A knot used to join two ropes or lines. Also see hitch.
Bermudan rig: A triangular mainsail, without any upper spar, which is hoisted up the mast by a single halyard attached to the head of the sail. This configuration, introduced to Europe about 1920, allows the use of a tall mast, enabling sails to be set higher where wind speed is greater.
Berth (moorings): A location in a port or harbour used specifically for mooring vessels while not at sea.
Berth (navigation): Safety margin of distance to be kept by a vessel from another vessel or from an obstruction, hence the phrase, "to give a wide berth."
Berth (sleeping): A bed or sleeping accommodation on a boat or ship.
Best bower (anchor): The larger of two anchors carried in the bow; so named as it was the last, best hope.
Between the devil and the deep blue sea: See devil seam.
Between wind and water: The part of a ship's hull that is sometimes submerged and sometimes brought above water by the rolling of the vessel.
Bight (/?ba?t/) –
1. Bight, a loop in rope or line—a hitch or knot tied on the bight is one tied in the middle of a rope, without access to the ends.
2. An indentation in a coastline.
Bilge: The compartment at the bottom of the hull of a ship or boat where water collects and must be pumped out of the vessel.
Bilge keels: A pair of keels on either side of the hull, usually slanted outwards. In yachts, they allow the use of a drying mooring, the boat standing upright on the keels (and often a skeg) when the tide is out.
Bilged on her anchor: A ship that has run upon her own anchor, so the anchor cable runs under the hull.
Bimini top: Open-front canvas top for the cockpit of a boat, usually supported by a metal frame.
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 or bitts: A post or pair mounted on the ship's bow, for fastening ropes or cables.
Bitter end: The last part or loose end of a rope or cable. The anchor cable is tied to the bitts; when the cable is fully paid out, the bitter end has been reached.
Block: A pulley or set of pulleys.
Blue Peter: A blue and white flag (the flag for the letter "P") hoisted at the foretrucks of ships about to sail. Formerly a white ship on a blue ground, but later a white square on a blue ground.
Boat: A small craft or vessel designed to float on, and provide transport over, or under, water.
Boat-hook: A pole with a hook on the end, used to reach into the water to catch buoys or other floating objects.
Boatswain or bosun (both /?bo?s?n/): A non-commissioned officer responsible for the sails, ropes, rigging and boats on a ship who issues "piped" commands to seamen.
Bobstay: A stay which holds the bowsprit downwards, counteracting the effect of the forestay. Usually made of wire or chain to eliminate stretch.
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.
Body plan: In shipbuilding, an end elevation showing the contour of the sides of a ship at certain points of her length.
Bombay runner: Large cockroach.
Bonded jacky: A type of tobacco or sweet cake.
Bonnet: A strip of canvas secured to the foot of the course (square sail) to increase sail area in light airs.
Booby: A type of bird that has little fear and therefore is particularly easy to catch.
Booby hatch: A sliding hatch or cover.
Boom: A spar attached to the foot of a fore-and-aft sail.
Boom gallows: A raised crossmember that supports a boom when the sail is lowered (obviates the need for a topping lift) .
Booms: Masts or yards, lying on board in reserve.
Boom vang or vang: A sail control that lets one apply downward tension on a boom, countering the upward tension provided by the sail. The boom vang adds an element of control to sail shape when the sheet 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.
Boomkin: See bumpkin.
Bore : i.e.Bore up or Bore away. To assume a position to engage, or disengage, the enemy ship(s)
Bosun: See boatswain.
Bottlescrew: A device for adjusting tension in stays, shrouds and similar lines.
Bottomry: Pledging a ship as security in a financial transaction.
Bow: The front of a ship.
Bow chaser: See chase gun
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.
Bow thruster: A small propeller or water-jet at the bow, used for manoeuvring larger vessels at slow speed. May be mounted externally, or in a tunnel running through the bow from side to side.
Boxing the compass: To state all 32 points of the compass, starting at north, proceeding clockwise. Sometimes applied to a wind that is constantly shifting.
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 monkey or brass monkey weather: Used in the expression "it is cold enough to freeze the balls off a brass monkey" (A brass monkey was a brass frame used to holdfast the bottom layer of a pyramid stack of cannon balls; when it was so cold the frame would shrink sufficiently to allow the cannon balls to collapse.)
Breakwater: A structure built on the forecastle of a ship intended to divert water away from the forward superstructure or gun mounts.
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.
1. (historically) A vessel with two square-rigged masts.
2. (in the US) An interior area of the ship used to detain prisoners (possibily prisoners-of-war, in war-time) & stowaways, and to punish delinquent crew members. Usually resembles a prison-cell with bars and a locked, hinged door.
Brightwork: Exposed varnished wood or polished metal on a boat.
Bring to: Cause a ship to be stationary by arranging the sails.
Broach: When a sailing vessel loses control of its motion and is forced into a sudden sharp turn, often heeling heavily and in smaller vessels sometimes leading to a capsize. The change in direction is called broaching-to. Occurs when too much sail is set for a strong gust of wind, or in circumstances where the sails are unstable.
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 watertight, load-bearing wall.
Bulwark (or Bulward)
Bulwark or Bulward (/?b?l?k/ in nautical use): The extension of the ship's side above the level of the weather deck.
Bumboat: A private boat selling goods.
Bumpkin or boomkin:
1. A spar, similar to a bowsprit, but which projects from the stern. May be used to attach the backstay or mizzen sheets.
2. An iron bar (projecting out-board from a ship's side) to which the lower and topsail brace blocks are sometimes hooked.
Bunting tosser: A signalman who prepares and flies flag hoists. Also known in the American Navy as a skivvy waver.
Buntline: One of the lines tied to the bottom of a square sail and used to haul it up to the yard when furling.
Buoy: A floating object of defined shape and color, which is anchored at a given position and serves as an aid to navigation.
Buoyed up: Lifted by a buoy, especially a cable that has been lifted to prevent it from trailing on the bottom.
Burgee: A small flag, typically triangular, flown from the masthead of a yacht to indicate yacht-club membership.
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.