|Glossary of nautical terms
This is a glossary of nautical terms; some remain current, many date from the 17th-19th century.
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
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' 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
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.
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.
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
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
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
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.
Bottomry – Pledging a ship as security in a financial transaction.
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
 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. Also known in the American Navy as a skivvy waver.
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.