Abaft
Toward the stern, relative to some object (“abaft the fore hatch”).
Abaft the beam
Further aft than the beam: a relative bearing of greater than 90 degrees from the bow: “two points abaft the port beam”.
Abeam
On the beam, a relative bearing at right angles to the centerline of the ship’s keel.
Aboard
On or in a vessel (see also close aboard).
Above board
On or above the deck, in plain view, not hiding anything.
Above-water hull
The hull section of a vessel above the waterline, the visible part of a ship. Also, topsides.
Accommodation ladder
A portable flight of steps down a ship’s side.
Adrift
Afloat and unattached in any way to the shore or seabed, but not under way. It implies that a vessel is not under control and therefore goes where the wind and current take her (loose from moorings, or out of place). Also refers to any gear not fastened down or put away properly. It can also be used to mean “absent without leave”.
Afloat
Of a vessel which is floating freely (not aground or sunk). More generally of vessels in service (“the company has 10 ships afloat”).
Afore
1.  In, on, or toward the front of a vessel.
2.  In front of a vessel.
Aft
1.  The portion of the vessel behind the middle area of the vessel.
2.  Towards the stern (of the vessel).
Ahead
Forward of the bow.
Ahoy
A cry to draw attention. Term used to hail a boat or a ship, as “Boat ahoy!”
Aloft
In the rigging of a sailing ship. Above the ship’s uppermost solid structure; overhead or high above.
Amidships (or midships)
In the middle portion of ship, along the line of the keel.
Anchor
1.  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 or plough-like object designed to grip the bottom under the body of water (but also see sea anchor).
2.  to deploy an anchor (“She anchored offshore.”)
Anchorage
A suitable place for a ship to anchor. Area of a port or harbor.
Apparent wind
The combination of the true wind and the headwind caused by the boat’s forward motion. For example, it causes a light side wind to appear to come from well ahead of the beam.
Astern
1.  Toward the stern (rear) of a vessel.
2.  Behind a vessel.
Avast
Stop, cease or desist from whatever is being done. From the Dutch hou’ vast (“hold fast”), from houd (“hold”) + vast (“fast”).
Awash
So low in the water that the water is constantly washing across the surface.
Aye, aye 
Reply to an order or command to indicate that it is understood
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

Barque (also bark)
A sailing vessel of three or more masts, with all masts but the sternmost square-rigged, the sternmost being fore-and-aft-rigged.
Barquentine (also barkentine)
A sailing vessel with three or more masts; with a square-rigged foremast and all other masts fore-and-aft rigged.
Batten
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.
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 midpoint 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.
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.
Becalmed
Unable to move due to lack of wind; said of a sailing vessel.
Belay
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.
Bermuda rig or 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.
Bermuda sloop
A fore-and-aft rigged sailing vessel with Bermuda rig developed in Bermuda in the 17th century. In its purest form, it is single-masted, although Bermuda sloops can have up to three masts, three-masted ships being referred to as schooners. Originally gaff rigged, but evolved to use Bermuda rig. The Bermuda sloop is the basis of nearly all modern sailing yachts.
Berth (sleeping)
A bed or sleeping accommodation on a boat or ship.
Bight 
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.
Binnacle
The stand on which the ship’s compass is mounted.
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.
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.
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.
Boom
A floating barrier to control navigation into and out of rivers and harbours..  A spar attached to the foot of a fore-and-aft sail.
Bosun
See boatswain.
Bow
1.  The front of a vessel.
2.  Either side of the front (or bow) of the vessel, i.e., the port bow and starboard bow. Something ahead and to the left of the vessel is “off the port bow”, while something ahead and to the right of the vessel is “off the starboard bow.” When “bow” is used in this way, the front of the vessel sometimes is called her bows (plural), a collective reference to her port and starboard bows synonymous with bow (singular) as described in Definition (1).
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.
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.
Breakwater
1.  A structure constructed on a coast as part of a coastal defense system or to protect an anchorage from the effects of weather and longshore drift.
2.  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.
Bridge wing
An open-air extension of the bridge to port or starboard, intended for use in signaling.
Brig
1.  (historically) A vessel with two square-rigged masts.
Brightwork
Exposed varnished wood or polished metal on a boat.
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.
Bulkhead
An upright wall within the hull of a ship. Particularly a watertight, load-bearing wall.
Bulwark or Bulward (/’b?l?k/ in nautical use)
Buoy
A floating object of defined shape and color, which is anchored at a given position and serves as an aid to navigation.
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”.
Cabin
an enclosed room on a deck or flat.
Capstan
A large winch with a vertical axis. A full-sized human-powered capstan is a waist-high cylindrical machine, operated by a number of hands who each insert a horizontal capstan bar in holes in the capstan and walk in a circle. Used to wind in anchors or other heavy objects; and sometimes to administer flogging over.
Captain
1.  The person lawfully in command of a vessel. “Captain” is an informal title of respect given to the commander of a naval vessel regardless of his or her formal rank; aboard a merchant ship, the ship’s master is her “captain.”
Catamaran
A vessel with two hulls.
Chafing
Wear on line or sail caused by constant rubbing against another surface.
Chain locker
A space in the forward part of the ship, typically beneath the bow in front of the foremost collision bulkhead, that contains the anchor chain when the anchor is secured for sea.
Cleat
A stationary device used to secure a rope aboard a vessel.
Clew
The lower corners of square sails or the corner of a triangular sail at the end of the boom.
Clew-lines
Used to truss up the clews, the lower corners of square sails.
Clipper
A very fast sailing ship of the 19th century that had three or more masts, a square rig, a long, low hull, and a sharply raked stem.
Close-hauled
Of a vessel beating as close to the wind direction as possible.
Companionway
A raised and windowed hatchway in the ship’s deck, with a ladder leading below and the hooded entrance-hatch to the main cabins.
Compass
Navigational instrument showing the direction of the vessel in relation to the Earth’s geographical poles or magnetic poles. Commonly consists of a magnet aligned with the Earth’s magnetic field, but other technologies have also been developed, such as the gyrocompass.
Cowl
1.  A ship’s ventilator with a bell-shaped top which can be swivelled to catch the wind and force it below.
Cringle
A rope loop, usually at the corners of a sail, for fixing the sail to a spar. They are often reinforced with a metal eye.
Crosstrees
two horizontal struts at the upper ends of the topmasts of sailboats, used to anchor the shrouds from the topgallant mast.
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 has become a generic term for what is properly called masthead. See masthead.
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.
Deckhead
The under-side of the deck above. The inside of the boat is normally paneled over to hide the structure, pipes, electrical wires. It can be in thin wood planks, often covered with a vinyl lining, or in thin PVC or now even in fiberglass planks.
Dhow
the generic name of a number of traditional sailing vessels with one or more masts with lateen sailsused in the Red Sea and Indian Ocean region, typically weighing 300 to 500 tons, with a long, thin hull. They are trading vessels primarily used to carry heavy items, like fruit, fresh water or merchandise. Crews vary from about thirty to around twelve, depending on the size of the vessel.
Dinghy
1.  A type of small boat, often carried or towed as a ship’s boat by a larger vessel.
2.  Also a small racing yacht or recreational open sailing boat, often used for beginner training rather than sailing full-sized yachts.
3.  Utility dinghies are usually rowboats or have an outboard motor, but some are rigged for sailing.
Dog watch
A short watch period, generally half the usual time (e.g. a two-hour watch rather than a four-hour one). Such watches might be included in order to rotate the system over different days for fairness, or to allow both watches to eat their meals at approximately normal times.
Downhaul
A line used to control either a mobile spar, or the shape of a sail. A downhaul can also be used to retrieve a sail back on deck.
Draft or draught 
The depth of a ship’s keel below the waterline.
Dress overall
To string International Code of Signals flags, arranged at random, from masthead to masthead (if the vessel has more than one mast) and then down to the taffrail, on a ship in harbor as a sign of celebration of a national, local, or personal anniversary, event, holiday, or occasion. When a ship is properly dressed overall, ensigns fly at each masthead unless displaced by another flag – for example, that of a flag officer on board – in addition to the ensign flown in the usual position at the stern.
Eye splice
A closed loop or eye at the end a line, rope, cable etc. It is made by unraveling its end and joining it to itself by intertwining it into the lay of the line. Eye splices are very strong and compact and are employed in moorings and docking lines among other uses.
Fairlead
A ring, hook or other device used to keep a line or chain running in the correct direction or to prevent it rubbing or fouling.
Fast
Fastened or held firmly (fast aground: stuck on the seabed; made fast: tied securely).
Fender
An air or foam filled bumper used in boating to keep boats from banging into docks or each other.
Fife rail
A freestanding pinrail surrounding the base of a mast and used for securing that mast’s sails’ halyards with a series of belaying pins.
Flotsam
Debris or cargo that remains afloat after a shipwreck. See also jetsam.
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
Fore-and-aft rig
A sailing rig consisting mainly of sails that are set along the line of the keel rather than perpendicular to it. Such sails are referred to as “fore-and-aft rigged.”
Forecastle
A partial deck, above the upper deck and at the head of the vessel; traditionally the sailors’ living quarters. Pronounced /’fo?ks?l/. The name is derived from the castle fitted to bear archers in time of war.
Forestays
Long lines or cables, reaching from the bow of the vessel to the mast heads, used to support the mast.
Foulies
A slang term for oilskins, the foul-weather clothing worn by sailors. See also oilskins.
Gaff rigged
A boat rigged with a four-sided fore-and-aft sail with its upper edge supported by a spar or gaffwhich extends aft from the mast.
Galley
Galley, the kitchen of a ship.
Gangplank
A movable bridge used in boarding or leaving a ship at a pier; also known as a “brow”.
Gangway
An opening in the bulwark of the ship to allow passengers to board or leave the ship.
Gash
Any refuse or rubbish which is discarded into a refuse container or dustbin
Gennaker
A large, lightweight sail used for sailing a fore-and-aft rig down or across the wind, intermediate between a genoa and a spinnaker.
Genoa or genny
A large jib, strongly overlapping the mainmast.
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.
Gooseneck
Fitting that attaches the boom to the mast, allowing it to move freely.
Goosewinged
Of a fore-and-aft rigged vessel sailing directly away from the wind, with the sails set on opposite sides of the vessel—for example with the mainsail to port and the jib to starboard, to maximize the amount of canvas exposed to the wind. See also running.
Gybe or jibe 
To change from one tack to the other away from the wind, with the stern of the vessel turning through the wind. (See also going about and wearing ship.)
Halyard or halliard
Originally, ropes used for hoisting a spar with a sail attached; today, a line used to raise the head of any sail.
Hand over fist
To climb steadily upwards, from the motion of a sailor climbing shrouds on a sailing ship (originally “hand over hand”).
Handsomely
With a slow even motion, as when hauling on a line “handsomely”.
Head
1.  The forwardmost or uppermost portion of the ship.
2.  The forwardmost or uppermost portion of any individual part of the ship, e.g., the masthead, thebeakhead, the stemhead, etc.
3.  The top edge of a sail.
4.  The toilet or latrine of a vessel, which in sailing ships projected from the bows and therefore was located in the “head” of the vessel.
Headsail
Any sail flown in front of the most forward mast.
Helm
A ship’s steering mechanism; see tiller and ship’s wheel. The wheel and/or wheelhouse area. See also wheelhouse.
Iron topsail
An auxiliary motor on a schooner.
Jacklines or jack stays
Lines, often steel wire with a plastic jacket, from the bow to the stern on both port and starboard. A crewmember clips his safety harness to a jackline, allowing him to walk along the deck while still being safely attached to the vessel.
Jib
A triangular staysail at the front of a ship.
Keel
The central structural basis of the hull.
Ketch
A two-masted fore-and-aft rigged sailboat with the aft mast (the mizzen) mounted (stepped) afore (in front of) the rudder.
Lanyard
A rope that ties something off.
Lazaret (also Lazarette or Lazaretto)
1.  A small stowage locker at the aft end of a boat.
2.  A ship or building used for quarantine of sick patients.
3.  An area on some merchant ships where provisions are stored.
4.  In modern shipbuilding and on powerboats of all sizes, the location of the steering gear equipment for the vessel.
Lee side
The side of a ship sheltered from the wind (cf. weather side).
Lee shore
A shore downwind of a ship. A ship which cannot sail well to windward risks being blown onto a lee shore and grounded.
Leech
The aft or trailing edge of a fore-and-aft sail; the leeward edge of a spinnaker; a vertical edge of a square sail. The leech is susceptible to twist, which is controlled by the boom vang, mainsheet and, if rigged with one, the gaff vang.
Leeway
The amount that a ship is blown leeward by the wind. See also weatherly.
Length between perpendiculars, also p/p, p.p., pp, LPP, LBP or Length BPP
The length of a vessel along the waterline from the forward surface of the stem, or main bow perpendicular member, to the after surface of the sternpost, or main stern perpendicular member. Believed to give a reasonable idea of the vessel’s carrying capacity, as it excludes the small, often unusable volume contained in her overhanging ends.
Length overall, or LOA
The maximum length of a vessel’s hull measured parallel to the waterline, usually measured on the hull alone, and including overhanging ends that extend beyond the main bow and main stern perpendicular members. For sailing vessels, this may exclude the bowsprit and other fittings added to the hull, but sometimes bowsprits are included.
Let go and haul
An order indicating that the ship is now on the desired course relative to the wind and that the sails should be trimmed (‘hauled’) to suit.
Letter of marque and reprisal or just Letter of marque
Luff
The forward edge of a sail.
Luffing
1.  When a sailing vessel is steered far enough to windward that the sail is no longer completely filled with wind (the luff of a fore-and-aft sail begins to flap first).
2.  Loosening a sheet so far past optimal trim that the sail is no longer completely filled with wind.
3.  The flapping of the sail(s) which results from having no wind in the sail at all.
Main deck
The uppermost continuous deck extending from bow to stern.
Mainsheet
Sail control line that allows the most obvious effect on mainsail trim. Primarily used to control the angle of the boom, and thereby the mainsail, this control can also increase or decrease downward tension on the boom while sailing upwind, significantly affecting sail shape. For more control over downward tension on the boom, use a boom vang.
Man the yards
To have all of the crew of a sailing vessel not required on deck to handle the ship go aloft and spread out along the yards. Originally used in harbors to display the whole crew to the harbor authorities and the other ships present to show that the vessel’s guns were not manned and hence her intentions were peaceful, manning the yards has since became a display used in harbor during celebrations and other special events.
Marlinspike
A tool used in ropework for tasks such as unlaying rope for splicing, untying knots, or forming a makeshift handle.
Mast
A vertical pole on a ship which supports sails or rigging. If a wooden, multi-part mast, this term applies specifically to the lowest portion.
Mess
An eating place aboard ship. A group of crew who live and feed together,
Nautical mile
a unit of length corresponding approximately to one minute of arc of latitude along any meridian arc. By international agreement it is exactly 1,852 metres (approximately 6,076 feet).
Outhaul
A line used to control the shape of a sail.
Parbuckle
A method of lifting a roughly cylindrical object such as a spar. One end of a rope is made fast above the object, a loop of rope is lowered and passed around the object, which can be raised by hauling on the free end of rope.
Pay off
To let a vessel’s head fall off from the wind (to leeward.)
Pilot
Navigator. A specially knowledgeable person qualified to navigate a vessel through difficult waters, e.g. harbour pilot etc.
Poop deck
A high deck on the aft superstructure of a ship.
Port
The left side of the boat. Towards the left-hand side of the ship facing forward (formerly Larboard). Denoted with a red light at night.
Port of registry
The port listed in a vessel’s registration documents and lettered on her stern. Often used incorrectly as a synonym for “home port”, meaning the port at which the vessel is based, but which may differ from her port of registry.
Port tack
When sailing with the wind coming from the port side of the vessel. Must give way to boats onstarboard tack.
Porthole or port
an opening in a ship’s side, esp. a round one for admitting light and air, fitted with thick glass and, often, a hinged metal cover, a window
Preventer (gybe preventer, jibe preventer)
A sail control line originating at some point on the boom leading to a fixed point on the boat’s deck or rail (usually a cleat or pad eye) used to prevent or moderate the effects of an accidental jibe.
Ratlines
The rungs fastened between the shrouds permanently rigged from bulwarks and tops to the mast to form ladders enabling access to the topmasts and yards.
Reaching
Sailing across the wind: from about 60° to about 160° off the wind. Reaching consists of “close reaching” (about 60° to 80°), “beam reaching” (about 90°) and “broad reaching” (about 120° to 160°). See also beating and running.
Ready about
A call to indicate imminent tacking (see going about).
Reef
1.  Reefing: To temporarily reduce the area of a sail exposed to the wind, usually to guard against adverse effects of strong wind or to slow the vessel.
2.  Reef: Rock or coral, possibly only revealed at low tide, shallow enough that the vessel will at least touch if not go aground.
Regatta
A series of boat races, usually of sailboats or rowboats, but occasionally of powered boats.
Rigging
The system of masts and lines on ships and other sailing vessels.
Rudder
A steering device which can be placed aft, externally relative to the keel or compounded into the keel either independently or as part of the bulb/centerboard.
Running rigging
Rigging used to manipulate sails, spars, etc. in order to control the movement of the ship. Cf. standing rigging.
Sail
1.  A piece of fabric attached to a vessel and arranged such that it causes the wind to drive the vessel along. It may be attached to the vessel via a combination of mast, spars, and ropes.
2.  The power harnessed by a sail or sails to propel a vessel.
3.  To use sail power to propel a vessel.
4.  A trip in a boat or ship, especially a sailboat or sailing ship.
Sail loft
A large open space used by sailmakers to spread out sails.
Sail-plan
A set of drawings showing various sail combinations recommended for use in various situations.
Sampan
A relatively flat bottomed Chinese wooden boat from 3.5 to 4.5 m long; some with a small shelter and may be used as permanent habitation on inland waters; generally used in coastal areas or rivers and as traditional fishing boats. It is unusual for a sampan to sail far from land as they do not have the means to survive rough weather.
Sampson post
A strong vertical post used to support a ship’s windlass and the heel of a ship’s bowsprit.
Schooner
A type of sailing vessel characterized by the use of fore-and-aft sails on two or more masts with the forward mast being no taller than the rear masts, first used by the Dutch in the 16th or 17th century.
Scuppers
Originally a series of pipes fitted through the ships side from inside the thicker deck waterway to the topside planking to drain water overboard, larger quantities drained through freeing ports, which were openings in the bulwarks.
Scuttle
A small opening, or lid thereof, in a ship’s deck or hull.
Seaboots
High waterproof boots for use at sea. In leisure sailing, known as sailing wellies.
Seacock
a valve in the hull of a boat.
Sextant
Navigational instrument used to measure a ship’s latitude.
Shakedown cruise
A cruise performed before a ship enters service or after major changes such as a crew change, repair, or overhaul during which the performance of the ship and her crew are tested under working conditions.
Shanghaied
Condition of a crewman involuntarily impressed into service on a ship.
Sheet
A rope used to control the setting of a sail in relation to the direction of the wind.
Shell (in the United Kingdom also fine boat)
An extremely narrow, and often disproportionately long, rowing boat outfitted with long oars, outriggers to hold the oarlocks away from the boat, and sliding seats, specifically designed for racing or exercise.
Ship
1.  Noun – Strictly, a three-masted vessel square-rigged on all three masts, or on three masts of a vessel with more than three. Hence a ship-rigged barque would be a four master, square-rigged on fore, main and mizzen, with spanker and gaff topsail only on the Jigger-mast. Generally now used refers to most medium or large vessels outfitted with smaller boats. As a consequence of this, submarines may be larger than small ships, but are called boats because they do not carry boats of their own.
2.  Verb – To bring something aboard swiftly, as in “Ship oars.”
Ship’s bell
Striking the ship’s bell is the traditional method of marking time and regulating the crew’s watches. Each bell (from one to eight) represents a 30-minute period since the beginning of a four-hourwatch. For example, in the classical system, “Three bells in the morning watch” represents 90 minutes since the beginning of the morning watch, or 5:30am. “Eight bells” indicates the end of a watch.
Shore leave
Free time given to officers and crew of a naval vessel when they are off duty and allowed to disembark and spend time on land. See also liberty.
Shrouds
Standing rigging running from a mast to the sides of a ships to support the mast sideways.
Skiff
A small boat, traditionally a coastal or river craft, for leisure or fishing, with a single person or small crew. Sailing skiffs have developed into high performance competitive classes.
Skysail
A sail set very high, above the royals. Only carried by a few ships.
Sloop
A small to mid-sized sailboat larger than a dinghy, with one mast bearing a main sail and head sail and located farther forward than the mast of a cutter.
Slush
Greasy substance obtained by boiling or scraping the fat from empty salted meat storage barrels, or the floating fat residue after boiling the crew’s meal. In the Royal Navy the perquisite of the cook who could sell it or exchange it (usually for alcohol) with other members of the crew. Used for greasing parts of the running rigging of the ship and therefore valuable to the master and bosun.
Slush fund
The money obtained by the cook selling slush ashore. Used for the benefit of the crew (or the cook).
Sounding.
Measuring the depth of the water. Traditionally done byswinging the lead, now commonly by echo sounding.
Sou’wester
1.  A storm from the south west.
2.  A type of waterproof hat with a wide brim over the neck, worn in storms.
Spanker
A fore-and-aft or gaff-rigged sail on the aft-most mast of a square-rigged vessel and the main fore-and-aft sail (spanker sail) on the aft-most mast of a (partially) fore-and-aft rigged vessel such as a schooner, a barquentine, and a barque.
Spar
A wooden, in later years also iron or steel pole used to support various pieces of rigging and sails. The big five-masted full-rigged tall ship Preussen (German spelling: Preußen) had crossed 30 steel yards, but only one wooden spar—the little gaff of its spanker sail.
Spinnaker
A large sail flown in front of the vessel while heading downwind.
Splice
To join lines (ropes, cables etc.) by unravelling their ends and intertwining them to form a continuous line. To form an eye or a knot by splicing.
Splice the mainbrace
A euphemism, it is an order given aboard naval vessels to issue the crew with a drink, traditionallygrog. The phrase splice the mainbrace is used idiomatically meaning to go ashore on liberty, intending to go out for an evening of drinking.
Spreader
A spar on a sailboat used to deflect the shrouds to allow them to better support the mast.
Spurling pipe
A pipe that connects to the chain locker, from which the anchor chain emerges onto the deck at the bow of a ship.
Squared away
Yards held rigidly perpendicular to their masts and parallel to the deck. This was rarely the best trim of the yards for efficiency but made a pretty sight for inspections and in harbor. The term is applied to situations and to people figuratively to mean that all difficulties have been resolved or that the person is performing well and is mentally and physically prepared.
Stanchion
vertical post near a deck’s edge that supports life-lines. A timber fitted in between the frame heads on a wooden hull or a bracket on a steel vessel, approx one meter high, to support the bulwark plank or plating and the rail.
Standing rigging
Rigging which is used to support masts and spars, and is not normally manipulated during normal operations. Cf. running rigging.
Starboard
The right side of the boat. Towards the right-hand side of a vessel facing forward. Denoted with a green light at night. Derived from the old steering oar or steerboard which preceded the invention of the rudder.
Starboard tack
When sailing with the wind coming from the starboard side of the vessel. Has right of way over boats on port tack.
Stay
Rigging running fore (forestay) and aft (backstay) from a mast to the hull.
Staysail
A sail whose luff is attached to a forestay.
Steerage
1.  The effect of the helm on a vessel; the act of steering a vessel.
Stem
The extension of keel at the forward end of a ship.
Stern
The rear part of a ship, technically defined as the area built up over the sternpost, extending upwards from the counter to the taffrail.
Strike the colors
To surrender the vessel to an enemy, from the custom during the Age of Sail of lowering the vessel’s ensign to indicate that she is surrendering.
Stopper knot
A knot tied in the end of a rope, usually to stop it passing through a hole; most commonly a figure-eight knot.
Stow
to store, or to put away e.g. personal effects, tackle, or cargo.
Stowage
the amount of room for storing materials on board a ship.
Stowaway
A trespasser on a ship; a person aboard a ship without permission and/or without payment, and usually boards undetected, remains hidden aboard, and jumps ship just before making port or reaching a port’s dock; sometimes found aboard and imprisoned in the brig until the ship makes port and the prisoner can be transferred to the police or military.
Swigging
To take up the last bit of slack on a line such as a halyard, anchor line or dockline by taking a single turn round a cleat and alternately heaving on the rope above and below the cleat while keeping the tension on the tail.
Swinging the compass
Measuring the accuracy in a ship’s magnetic compass so its readings can be adjusted—often by turning the ship and taking bearings on reference points.
Swinging the lamp
Telling sea stories. Referring to lamps slung from the deckhead which swing while at sea. Often used to indicate that the story teller is exaggerating.
Swinging the lead
1.  Measuring the depth of water beneath a ship using a lead-weighted sounding line. Regarded as a relatively easy job, thus:
2.  Feigning illness etc to avoid a hard job.
Tack
1.  A leg of the route of a sailing vessel, particularly in relation to tacking (q.v.) and to starboard tack and port tack (also q.v.).
2.  Hard tack: q.v..
3.  The front bottom corner of a sail.
Tacking
1.  Zig-zagging so as to sail directly towards the wind (and for some rigs also away from it).
2.  Going about (q.v.).
Taffrail
A rail at the stern of the boat that covers the head of the counter timbers.
Taken aback
An inattentive helmsmen might allow the dangerous situation to arise where the wind is blowing into the sails ‘backwards’, causing a sudden (and possibly dangerous) shift in the position of the sails.
Thwart 
A bench seat across the width of an open boat.
Tiller
a lever used for steering, attached to the top of the rudder post. Used mainly on smaller vessels, such as dinghies and rowing boats.
Toe-rail
A low strip running around the edge of the deck like a low bulwark. It may be shortened or have gaps in it to allow water to flow off the deck.
Toe the line or Toe the mark
At parade, sailors and soldiers were required to stand in line, their toes in line with a seam of the deck.
Tompion
A block of wood inserted into the barrel of a gun on a 19th-century warship to keep out the sea spray; also used for covers for the ends of the barrels of more modern ships’ guns, the larger of which are often adorned with the ship’s crest or other decoration.
Tonnage
Various measures of the size or cargo carrying capacity of a ship, including:
1. Deadweight tonnage, the total weight of a vessel, mostly without payload.
2.  Displacement tonnage, the total weight of a vessel.
3.  Gross register tonnage, the total internal volume of a vessel, with one gross register ton equal to 100 cubic feet (2.8316846592 cubic meters).
4.  Gross tonnage, a function of the volume of all of a ship’s internal spaces.
5.  Lightship or lightweight tonnage, the weight of a ship without any fuel, cargo, supplies, water, passengers, etc. on board.
6.  Net register tonnage, the volume of cargo a vessel can carry.
7.  Net tonnage, the volume of all cargo spaces on a ship.
8.  Thames Measurement tonnage, the volume of a small vessel calculated based on her length and beam.
Top
The platform at the upper end of each (lower) mast of a square-rigged ship, typically one-fourth to one-third of the way up the mast. The main purpose of a top is to anchor the shrouds of the topmast that extends above it. See also fighting top.
Topgallant
The mast or sails above the tops. (See topgallant mast and topgallant sail.)
Topman
A crewmember stationed in a top.
Topmast
The second section of the mast above the deck; formerly the upper mast, later surmounted by thetopgallant mast; carrying the topsails.
Topsail
The second sail (counting from the bottom) up a mast. These may be either square sails or fore-and-aft ones, in which case they often “fill in” between the mast and the gaff of the sail below.
Topsides
the part of the hull between the waterline and the deck. Also, Above-water hull
Touch and go
1.  The bottom of the ship touching the bottom, but not grounding.
2.  Stopping at a dock or pier for a very short time without tying up, to let off or take on crew or goods.
3.  Practice of aircraft on aircraft carriers touching the carrier deck and taking off again without dropping hooks.
Transom
The aft “wall” of the stern; often the part to which an outboard unit or the drive portion of a sterndrive is attached. A more or less flat surface across the stern of a vessel. Dinghies tend to have almost vertical transoms, whereas yachts’ transoms may be raked forward or aft.
Travellers
Small fittings that slide on a rod or line. The most common use is for the inboard end of the mainsheet; a more esoteric form of traveller consists of “slight iron rings, encircling the backstays,
Trice
To haul and tie up by means of a rope.
Trick
A period of time spent at the wheel (“my trick’s over”).
Turn To (Two)
A term meaning “Get to work,” often hand-signed by two fingers and hand motion in turning fashion.
Tweendeck
A deck on a general cargo ship located between the main deck (or weather deck) and the holdspace. A general cargo ship may have one or two tweendecks (or none at all).
Two six heave
Royal Navy slang term meaning to pull. Originally a sailing navy term referring to the two members of a gun crew (numbers two and six) who ran out the gun by pulling on the ropes that secured it in place.
Tye
A chain or rope used for hoisting or lowering a yard. A tye runs from the horizontal center of a given yard to a corresponding mast and from there down to a tackle. Sometimes specifically called a chain tye or a rope tye.
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Under way or underway
A vessel that is moving under control: that is, neither at anchor, made fast to the shore, aground nor adrift.
Vang
1.  A rope (line) leading from gaff to either side of the deck, used to prevent the gaff from sagging.
2.  See boom vang.
Wake
Turbulence behind a vessel. Not to be confused with wash.
Waft
A signal flag on a vessel.
Watch
A period of time during which a part of the crew is on duty. Changes of watch are marked by strokes on the ship’s bell.
Waterline
The line where the hull of a ship meets the water’s surface.
Way
Speed, progress, or momentum. To make way is to move; to lose way is to slow down.
Waypoint
A location defined by navigational coordinates, especially as part of a planned route.
Wearing ship
Tacking away from the wind in a square-rigged vessel. See also gybe.
Weather deck
Whichever deck is that exposed to the weather—usually either the main deck or, in larger vessels, the upper deck.
Weather gage or weather gauge or weather-beam
Favorable position over another sailing vessel with respect to the wind.
Weather side
The side of a ship exposed to the wind.
Weigh anchor
To heave up (an anchor) preparatory to sailing.
Whiskers
Spreaders from the bows to spread the bowsprit shrouds.
Wind-over-tide
Sea conditions with a tidal current and a wind in opposite directions, leading to short, heavy seas.
Windage
Wind resistance of the boat.
Windlass
A winch mechanism, usually with a horizontal axis. Used where mechanical advantage greater than that obtainable by block and tackle was needed (such as raising the anchor on small ships).
Windward
In the direction that the wind is coming from.
Wing
An extension on the side of a vessel. A bridge wing is an open-air extension of the bridge to port or starboard, intended for use in signaling.
Yacht
A recreational boat or ship; the term includes sailing yachts, motor yachts, and steam yachts.
Yard
1.  Yard: The horizontal spar from which a square sail is suspended.
2.  A dockyard or shipyard.
Yardarm
The very end of a yard. Often mistaken for a “yard”, which refers to the entire spar. As in to hang “from the yardarm” and the sun being “over the yardarm” (late enough to have a drink).
Yawl
A fore-and-aft rigged sailing vessel with two masts, main and mizzen, the mizzen stepped abaft the rudder post.