Glossary of Nautical and Sailboat Terms and Phrases

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Basic and common nautical and basic sailboat terms and phrases dictionary contains all the usage of terms and their meanings as well as navigational terms. Nautical sailing terms and phrases basic nautical terms and a list of common sailing terms for beginners.

Here is a range of basic and common nautical sailing terms and phrases with their meanings as well as navigational terms :


Aback - A sail is said to be aback when its clew is to windward and the wind is pressing it against the mast, for instance when the boat is hove-to, or as a result of a sudden change in the wind.

Abaft - Toward the stern.

Abeam - At right angles to the centreline of a boat.

About - To go about is to change tack.

Adrift - Free-floating, without power or control.

Aft - At, toward, near or behind the stern

Afterpart - The part of a boat aft of the beam.

A-hull - A boat is lying a hull when hove-to with all sails furled (see also Lie).

Aloft - Above the deck.

Amidships - Midway between the stern and the stern of a boat.

Anabatic wind - A wind created by air blowing up a slope- It is the - result of the air at the bottom of the slope being warmer than the air at the top, and rising by convection (see also Katabatic wind).

Anchor light - An all round white light displayed at night (usually on the forestay) by an anchored vessel. Also called a riding light.

Anchor rode - An anchor line.

Antifouling - A protective compound (usually a paint) applied to a hull to inhibit the growth of marine life, such as barnacles, on it.

Apparent wind - The perceived wind flowing over a moving boat. It is the resultant of the speed and direction of the true wind and the speed and direction of the boat (see also True wind).

Aspect ratio - The ratio of the length of the foot of a sail to the length of its luff. A tall, narrow sail has a high aspect ratio, and a low, broad sail has a low aspect ratio.

Astern - Behind a boat. To go astern means to reverse.

Athwart - from side to side across the centreline of a boat.

Auxiliary engine - An engine, outboard or inboard, used to power a sailboat.

Avast - 'Stop!' (see also Belay).

Aweigh - An anchor is said to be aweigh when it has come free of the ground.


Back - To push a sail out so that the wind fills it from the other side.

Backstay - A stay leading aft from the masthead.

Ballast - Weight (usually metal) placed in the bottom of a boat or fitted to the keel to increase stability.

Bar - An offshore ridge of sand, mud or shingle, parallel to the shore and across the mouth of a river or bay or the approach to a harbour.

Barber hauler - A line or tackle attached to a sheet, at a point between the clew and the fairlead, which is used to adjust the angle of shooting.

Battens - Thin strips of wood or plastic inserted into pockets in a sail to preserve its shape.

Beam - The maximum width of a boat.

Bear away - To change course away from the wind.

Bear down - To approach from upwind.

Bearing - The direction of an object expressed in compass notation.

Beating - To sail to windward by repeated tacking.

Becket - A small loop or eye in the end of a rope or on a block.

Before the wind: - Said of a sailing vessel when the wind is coming from aft, over the stem.

Belay - To secure a rope to a cleat or a belaying pin; an instruction meaning 'Stop!' (see also Avast).

Bend - One of various types of knot; to knot two ropes together; to attach a sail to a spar.

Bermudan rig - A rig with a triangular mainsail. Also known as a Marconi rig.

Berth - The place where a vessel lies. The place in which a person sleeps.

Bight - Any part of a rope between its ends; a curve or loop in a rope; a wide indentation in a coastline, or the water bounded by that indentation.

Bilge - The part of a vessel's hull where the side curves in to form the bottom; the part of a vessel between the lowermost floorboards and the bottom, where water often collects.

Bill - The point at the extremity of a fluke of an anchor.

Binnacle - A receptacle placed near the helm containing the compass.

Bitter end - The end of a line or chain, especially the end secured in the chain locker or to the bitts.

Bitts - A pair of small posts on the deck of a vessel for securing mooring lines.

Blade - The flat part of an oar which goes into the water.

Block - A casing containing one or more freely-rotating pulley wheels (sheaves).

Board - The stretch a vessel makes upon one tack when she is beating.

Bollard - A sturdy wood or metal post, fixed to a quay or wharf, to which mooring lines are attached.

Bolt rope - A strong rope sewn around the edge of a sail to reinforce it.

Boom - A spar used to extend the foot of a fore-and-aft sail, such as a mainsail, and to control its position relative to the wind.

Boom preventer - A line or tackle that prevents unwanted movement of a boom, such as an accidental gybe.

Boom vang - A line or tackle that prevents the boom from riding up when the mainsail is set. Also called a kicking strap.

Boot hook - A metal or plastic hook, with a long staff, for picking up mooring buoys, hooking temporarily to piers.

Boot top - A stripe painted around the hull above the waterline, separating the bottom paint from the topside finish.

Buoy - A floating cask, or piece of wood, attached by a rope to an anchor, to show its position. Also floated over a shoal. or other dangerous place as a beacon.

Bosun's chair - A canvas bucket scat on which a person can be hoisted up a mast.

Bow - The forward end or part of a vessel.

Bower - A main anchor carried at the bow of a vessel.

Bowline - A knot tied in the end of a line to form a loop that will not slip.

Bow line - A mooring line attached to the bow of a boat.

Bowsprit - On some boats, a heavy spar projecting ahead from the bow, enabling headsails to be set farther forward.

Break out - To bring something out of stowage, such as a sail from a bag or food from a locker.

Breast-hooks - Knees in the forward part of a vessel, across the stem, to secure the bows.

Breast line (breast rope) - A rope, used for tying up to a jetty, which is led from forward or aft at right angles to the side of the vessel.

Bridle - A line which is attached to the centre of another line which is made fast at both ends.

Bring up - To stop or come to anchor.

Broach to - To swerve sharply and dangerously in a following sea, slewing broadside-on to the waves.

Bulkhead - An upright, wall-like partition within a boat.

Bulwarks - A solid, fence like parapet along the outer sides of a deck.

Bumpkin - A spar protruding over the stern to carry a standing backstay.

Bunt - The middle of a sail

Burdened vessel - The boat not having the right of way.

Burgee - A small, triangular or swallow tailed flag, flown from the mast of a yacht to indicate the owner's membership of a particular yacht club, or to act as an indicator of the apparent wind direction.

Butt: - The end of a plank where it unites with the end of another.

By the head - Having greater draught forward than aft (see also By the stern).

By the lee - Sailing on a run with the wind over the same side as the mainsail (over the lee side). This can result in an accidental gybe.

By the stern - Having greater draught aft than forward (see also By the head).


Cable - An anchor chain or rope; one tenth of a nautical mile.

Camber - The curve of a set sail; the slight upward curve from the side to the centre of a deck.

Capstan - A vertical drum for hauling in or letting out the anchor chain.

Cap shroud - Wire led from either side of mast over spreader down to side deck to support upper section of spar.

Careen - To heel a vessel onto one side so as to be able to work on her bottom.

Carvel-built - Having a wooden hull whose planks are made flush at the seams (see also Clinker-built).

Carlings - Pieces of timber running between the deck beams.

Carry-away - To break a spar, or part a rope.

Cast - To pay a vessel's head off, in getting under way, on the tack she is to start upon. To cast off a line is to let go.

Cast off - To release the lines securing a boat to a dock or mooring.

Catamaran - A vessel with twin hulls

Cat's paw - A kind of hitch made in a rope. A light current of air on the surface of the water.

Caulk - To fill the seams of a vessel with oakum or caulking cotton.

Caulking - Waterproof material packed into the seams between planks to make the structure watertight.

Centre of effort - The combined centre of area of all sails on a boat.

Centre of gravity - The point in a boat where all weights balance each other.

Centre of lateral resistance - The centre of area of the underwater profile of a hull.

Cavitation - Propeller slippage caused by a cavity of air pulled down from the surface.

Centreboard - A pivoting wooden board let down through the bottom of a sailboat to provide lateral stability and reduce leeway (see also Daggerboard, Keel, Leeboards, Leeway).

Centreline - The fore-and-aft line through the centre of a boat.

Chain plates - The metal fittings at the sides of a boat to which the shrouds are attached.

Chart - An accurate representation on paper of the navigational characteristics of a body of water and Its surrounding land areas.

Chart datum - The water level – usually the level of the lowest astronomical tide from which all depths shown on a chart are measured.

Check - To stop or impede, as to check to cable from paying out.

Chine - A sharp angle between the side and the bottom of a boat.

Chord - An imaginary straight line, parallel to the foot, joining the leading edge (luff) and trailing edge (leech) of a sail.

Clamps - Thick planks on the inside of vessels, to support the ends of beams.

Claw ring - A C-shaped fitting, slipped over the boom when the sail has been roller-reefed, that allows the kicking strap (vang) to be re-attached.

Cleat - A two-armed metal or wooden fitting to which ropes can be secured

Clew - The lower aft corner of a fore-and-aft sail, where the leech meets the foot.

Clinker - Lapstrake planking, in which planks overlap at the edges, as distinguished from cavel (smooth).

Clinker-built - Having a wooden hull whose planks overlap at the seams (see also Carvel-built).

Close-hauled - Sailing as close to the wind as possible.

Clove-hitch - Two half-hitches round a spar or other rope .

Coach roof - The part of the cabin built up above deck level.

Coaming - This vertical, or nearly vertical, structure round the cockpit and the sides of the cabin top. Any vertical member to stop water entering, as for instance below a deckhouse door, is also a coaming.

Cockpit - The well at the stern of a sailboat, where the helmsman stands or puts his feet.

Coffee grinder - A large, pedestal mounted sheet winch with two handles on a horizontal spindle.

Committee boat - In racing, the boat carrying the race officials.

Companion - A wooden covering over the staircase to a cabin. A companion-way, the staircase to the cabin.

Companionway - A stairway or ladder leading from the deck to the cabin or saloon.

Compass - The instrument which shows the course of a vessel.

Conning - Directing the helmsman in steering a vessel.

Crab - To catch a crab is to catch the oar in the water by feathering it too soon.

Cringle - An eye or loop set in the bolt rope of a sail.

Cross-trees - Struts on each side of a mast to increase the spread and holding power of the main shrouds. Also called spreaders.

Crutch - Support for a boom.

Cuddy - A cabin in the fore part of a boat,

Cunningham hole - An eye in the luff of a sail, just above the tack, to which a tackle (Cunningham tackle) is attached to adjust the luff tension.

Cutter - A single-masted boat rigged with a staysail and jib. It may be Bermudan-rigged or gaff-rigged.


Daggerboard - A sliding wooden board let down through the bottom of a sailboat to provide lateral stability and reduce leeway (see also Centreboard, Keel, Leeboards, Leeway) -

Day mark - An indicator, usually a white-painted shape, which marks a shore feature by day.

Day-sailer - A sailing boat with limited accommodation, suitable for short passages but not for extensive cruising.

Dead reckoning - Navigating by using the measured speed, elapsed time and course steered from a known - position to calculate the boat's present position (see also Fix, Observed position).

Deadrise - Angle of the bottom between chine and keel to the horizontal.

Deck - The structure completely or partially covering the interior of a boat.

Deckhead - The underside of a deck; the roof of a boat's cabin or saloon.

Dead-wood - Blocks of timber, laid upon each end of the keel, where the vessel narrows.

Dinghy - A small boat used as a tender for a larger boat; sailing dinghies now have been developed into one-design racing classes (the name was derived from an East Indian rowboat).

Displacement - The weight of sea-water, expressed in tons of 2240 pounds, displaced by the submerged part of a boat when it is afloat; it always exactly equals the weight of the boat itself; it can be calculated by dividing the number of cubic feet in the submerged part of the bilge by 35.

Diamond - Stay to support centre of the mast laterally.

Dinghy - A small boat used as a tender for a larger boat; sailing dinghies now have been developed into one-design racing classes (the name was derived from an East Indian rowboat).

Displacement - The weight of sea-water, expressed in tons of 2240 pounds, displaced by the submerged part of a boat when it is afloat; it always exactly equals the weight of the boat itself; it can be calculated by dividing the number of cubic feet in the submerged part of the bilge by 35.

Displacement hull - A hull designed to pass through the water, rather than skim over the surface.

Dock - The planked floor of vessel, resting upon the beams.

Dodger - A canvas strip fitted between the guardrail and the gunwale of a yacht to protect the crew from spray.

Doghouse - Raised section at after end of cabin.

Dolphin - A pile, post or buoy for mooring a vessel in a harbour.

Dorade ventilator - A cowl ventilator built into a box; it contains a pipe leading below deck and arranged so that water entering a cowl will be carried out through scuppers, but so air will be admitted to the interior of the boat.

Double-ender - A boat which has a hull that is pointed at bow and stern.

Douse - To lower (a sail) in haste; also, to stow.

Downhaul - A rope or tackle used to haul down a sail (such as a spinnaker) or to tension the luff of a sail by pulling down the tack (see also Uphaul).

Downwind - In the opposite direction of the wind.

Draught - The depth of water occupied by a vessel, measured as the vertical distance from the waterline to the lowest point of the hull or keel.

Drogue - An object, such as a canvas sea anchor, towed behind a boat to reduce its speed.

Drying features - Features, such as sandbanks, which are covered at high water but exposed as the tide drops.

Dry rot - The decay of timber caused by several types of fungi, usually under moist, unventilated conditions at temperatures above 72 degrees.


Ease - To let out a line, sheet or anchor chain gradually.

Ebb tide - The flowing back of the tide from high to low water (see also Flood tide).

Ensign - A flag flown by a vessel to indicate its nationality.

Eye splice - A loop formed in the end of a line by splicing it back on the standing part.

Eye of a vessel - The extreme forward part.


Fairlead - A channel, ring, eye, loop or bolt for guiding a rope in the required direction.

Fairway - The main shipping channel in restricted waters.

Fall - The part of the rope, leading from a tackle, that is hauled on.

Fathom - A unit of measurement of water depth, equal to 6 feet (1.83 metres).

Feather - To feather an oar in rowing, is to turn the blade horizontally with the top forward as it comes out of the water, so as not to take the wind or dip up water. In sailing, it is to point the boat higher into the wind to take pressure from the sails in a hard gust.

Fender - A device, fitted with short lines for securing, to protect the sides of a boat from rubbing against an object; it is made of canvas cylinder filled with ground cork, or flexible plastic filled with air or of plaited rope.

Fend off - To push a hull away from an object or another boat.

Fetch - To sail close-hauled without tacking.

Fid - A tapered, wooden tool for spreading the strands of rope when splicing.

Fin keel - A single, centrally-placed and ballasted keel (see also Keel).

Fix - A vessel's position, as obtained b@ taking accurate bearings (see also Dead reckoning, Observed position).

Flame arrester - A screened cap placed over the carburettor intake to prevent backfires from igniting bilge vapours.

Flare - When a vessel's sides go out from the perpendicular The opposite to tumble-home.

Flood tide - A rising or flow tide (see also Ebb tide).

Floors - The structural members of a boat that tie her together across the keel-not the part of the cabin that you walk on, which is the cabin sole.

Flukes - The pointed parts of an anchor that dig into the ground.

Flush deck - A type of design in which no house protrudes above deck, and the cabin beams extend bill width.

Flying bridge - A control station on top of the deckhouse deck that provides high visibility for deep sea fishing and navigation.

Following sea - A sea travelling in the same direction as the boat (see also Head sea).

Foot - The bottom edge of a sail.

Fore - At, toward or near the bow.

Forefoot - The forward part of the keel, adjoining the lower part of the stem.

Fore-and-aft - Along or parallel to the centreline.

Foresail - A triangular sail, such as a jib, set ahead of the main mast (see also Headsail).

Forestay - A stay leading from the masthead to the bow.

Forward - Toward the bow.

Freeboard - The distance between the deck and the waterline.

Freshen - To increase in strength (wind).

Furl - To roll a sail and fasten it to it, boom when it is not in use (see also Reef).


Gaff - The spar that supports the head of a gaffsail.

Gaff-rigged - Having one or more gaffsails.

Gaffsail - A four-sided, fore-and-aft sail.

Galley - The kitchen of a yacht.

Garboard-strake - The planks next to the keel, on each side.

Gaskets - The small cords used to tie up a furled sail. Also called ties or furling lines.

Gel coat - The final resin glass coating of a fibreglass hull containing the colour pigment.

Genoa - A large foresail that extends aft beyond the mainmast.

Gimbals - A pair of pivoted, concentric rings used to hold a compass or stove horizontal, regardless of the motion or the boat.

Gnomonic projection - A type of map or chart projection with straight longitude lines and curved latitude lines (see also Mercator projection).

Go about - To turn a boat head-to-wind to change tack.

Gooseneck - A pivoted fitting that secures a boom to a mast.

Goosewing - To sail downwind with the mainsail set on one side and the foresail on the other.

Grab rails - Rails bolted to cabin decks for use as hand holds in steadying oneself.

Grapnel - A small anchor with several claws.

Grommet - A brass eye fitted into the edge of a sail, duffle bag, or other piece of canvas to take the wear of a line. A ring formed of rope, by laying around a single strand.

Ground tackle - General term for anchors, cables, warps, springs, etc.; anything used for securing a vessel at anchor.

Gudgeons - Metal eye set into transom (or tuck) of boat to take pintle set into rudder; alternatively, gudgeon may be set into rudder to take pintle set into transom (or tuck).

GRP - Glass-reinforced plastic, made by impregnating glassfibre matting with resins such as polyesters.

Gunter rig - A rig in which gaff is used as an extension of the main mast.

Gunwale - (or gunnel) - The top edge of the side of the hull.

Guy - A rope or wire used to steady a spar.

Gybe - To move a fore~and-aft sail from one - side of the boat to the other when changing course on a run.


Halyards - Popes or wires used to hoist sails.

Hanks - Clips or rings that attach sails to stays.

Hard chine - Where topsides join the bottom at a sharp angle.

Hard over - Extreme position of the helm.

Harden - up - To sail closer to the wind.

Hatch - A opening in the dock.

Hawse pipes - Bow pipes through which the anchor cables pass.

Hawser - A heavy rope used for towing, mooring or warping.

Heading - The compass direction in which i - boat is pointing.

Headsail - A sail, such as a spinnaker, set forward of the main mast (see also Foresail).

Head sea - A sea travelling in - the opposite direction to that of the boat (see also Following sea).

Heads - The toilets on a boat.

Head-to-wind - With the bow pointing into the wind.

Heave-to - To stop a boat, for instance by backing the foresail or by letting the sails flap on a beam reach.

Heaving line - A light rope thrown ashore when berthing and used to haul a heavier mooring line ashore.

Heel - To lean over or list; the bottom of a mast; the aft end of a keel.

Helm - The tiller or wheel.

Helmsman - The person steering a boat.

Hitch - To tie a rope to a spar or stay; a knot - that can be undone by pulling against the direction of the strain that holds it tight.

Horse (or hawse) - The metal track, bar, or wire on which the traveller carrying the centre block of the mainsheet slides.

Holding ground - Ground that an anchor can dig into.

Hounds - The part of the mast to which the shrouds and stays are attached.

Hull - The body of a vessel.

Hydroplane - A hull designed, by means of steps in the bottom, to rise to the surface of the water and skim over the water.


Inboard - Situated within the hull; toward the centreline.

Inshore - Close to the shore; toward the shore from the water.

In stays - Midway between changing tacks when boat is headed into wind.

In stops - A sail tuned temporarily and held in place with weak thread so it can be broken out quickly this is common practice for spinnakers when racing.

Irons - A boat is said to be 'in irons when it is pointing directly into the wind and unable. to move forward.

Isobars - Lines on a weather map joining points of equal barometric pressure.

IYRU - The International Yacht Racing Union, which is the controlling body for international yacht racing.


Jamming cleat - A cleat into which a rope may be jammed to secure it.

Jib - A triangular sail attached to the forestay.

Jumper struts - Spreaders that are angled forward so that they give support fore-and-aft as well as sideways. The stays running over them are known as Jumper stays.

jury rig - A temporary replacement for damaged rigging.


Katabatic wind - A wind created by air flowing down a slope. It usually occurs at night, when the air at the - top of a slope cools quicker, and - so becomes heavier, than the air at the bottom (see also Anabatic wind).

Kedge - A small anchor used in conjunction - with the main anchor; to move a boat by deploying the kedge and pulling on it.

Keel - The underwater extension of the hull of a sailing boat that provides lateral stability and reduces leeway. it is usually fixed, but on some - boats can be raised and lowered (see also Centreboard, Daggerboard, Leeboards, Leeway).

Keelson - A timber placed over the keel on the floor-timbers, and running parallel with it.

Ketch - A two-masted boat, rigged fore-and-aft. The forward mast is the main mast, the aft mast is called the mizzen.

Kicking strap - A line or tackle that prevents the boom front riding up when the mainsail is set. Also called a boom vang.

Knees - Crooked pieces of timber, having two arms, used to connect the beams of a vessel with her timbers.

Knot - A speed of one nautical mile per hour (see also Nautical mile).


Land breeze - A breeze blowing from the land. - It occurs mainly - at night and in the early morning, when the land is cooler than the sea because it has lost more heat after sunset (see also Sea breeze).

Landfall - To sight or arrive at land.

Lanyard - A short length - of rope or cord tor attaching one thing to another.

Lash - To tie something in place by binding it tightly with light rope.

Latitude - The angular distance of a position in degrees north or south of the equator (see also Longitude).

Launch - To slide or lower a vessel into the water; a small motor-driven tender.

Lay up - To take a boat out of rise, for example during the winter.

Lee - The area downwind (to leeward) of a boat or other object (see also Weather).

Lee shore - The shore upon which the wind is blowing. Under the lee of anything, is when you have that between you and the wind.

By the lee - A vessel, going free, when she has fallen off so much as to bring the wind around her stern, and to take her sails aback on the other side.

Leeboards - Boards fixed vertically to the sides of a boat's hull to provide lateral stability and reduce leeway (see also Centreboard, Daggerboard, Keel, Leeway).

Leech - The rear edge of a fore-and-aft sail.

Lee side - The downwind (leeward) side of a boat or other object (see also Weather side).

Lee tide - A tide running with the wind (see also Weather tide).

Leeward (Loo'ard) - Toward the lee side; the direction to which the wind is blowing (see also Windward).

Leeway - The sideways drift of a vessel, to leeward, caused by the wind; the distance between the course steered and the course actually run.

Let fly - To let go a sheet so as to spill the wind from the sail it controls.

Lie - To keep a boat stationary; to keep a boat as steady as possible during a gale, for instance by lying a-hull (see also A-hull).

Lifeline - A safety line for the crew to hang onto, fitted fore-and-aft or around the deck.

Lift - A rope or wire supporting a spar (see also Topping lift).

Limbers, or limber holes - Holes cut in the lower part of the floor-timbers, each side of the keel, so as to allow water to flow fore-and-aft.

Line squall - A usually violent squall accompanying the cold front of a depression. Its low black cloud forms a distinct line or arch.

List - The inclination of a vessel to one side; as a list to port, or a list to starboard.

L.O.A. - Length overall of a boat, but not including any spars outboard such as bowsprit or bumpkin.

Log - An instrument used to measure a boat's speed through the water; a book (logbook) in which the details of a boat's voyages are recorded.

Longitude - The angular distance of a position in degrees cast or west of the Greenwich Meridian (0°) (see also Latitude, Meridian).

Loom - The reflection on - the clouds of the light front - a lighthouse or lightship, when the - light itself is still below the horizon. - That part of an oar which is within the row-lock.

Loose - To let go of a rope; to unfurl or set a sail.

Loose-footed - A loose-footed sail is one whose foot is knot - laced to a boom.

Low water - Low tide.

Lubber line - The line marked on compass to indicate the fore-and-aft axis of the vessel.

Luff - The forward edge of a sail; to bring a boat closer to the wind.

Luff up - To turn a boat directly into the wind.

Lug - (lugsail) - A four-sided, fore-and-aft sail.

Lugger - A boat rigged with a lugsail.

L.W.L. - Load water line of a vessel-the line to which she floats when at her designed weight.


Main saloon - The principal cabin of a boat.

Main sheet - The line controlling the main boom.

Make - To make sail is to set it. To make fast is to secure a line to a bitt, cleat, etc.

Make fast - To secure a rope.

Marconi - A rig with a triangular mainsail. Also known as a Bermudan rig.

Mark - A. fixed onshore or offshore feature used as a guide when navigating.

Marlin(e) spike - A pointed metal or wooden spike used for separating the strands of a rope to splice it.

Mast - A vertical pole or set of poles for supporting a sail or sails.

Masthead rig - When headsail is hoisted to the masthead.

Mast gate - The fixture that secures the mast of a dinghy where it passes through the foredeck.

Masthead - The top section of a mast.

Masthead sloop - A sloop on which the forestay (which carries the foresail) extends from the bow to the masthead.

Mast step - A fixture into which the foot of the mast is fitted, either on the deck (for a deck-stepped mast) or on top of the keel (for a keel-stepped mast).

Mercator projection - A type of map or chart projection with straight longitude and latitude lines crossing at right angles (see also Gnomonic projection)

Meridian - An imaginary circle drawn around the earth and passing through both poles. All lines of longitude are meridians (see also Longitude).

Messenger - A line used for heaving in a heavier one.

Midships - The broadest part of a vessel.

Mile - A nautical mile is on sixtieth of a degree of latitude, generally 6080 feet.

Millibar - A unit of barometric pressure, used on weather maps. 1000 millibars ( - 1 bar) is equal - to 29.53 inches of mercury. From the earth's surface, atmospheric pressure decreases by about one millibar for every 28 - feet (8.5 metres) of increase in altitude.

Miss stays - When tracking a boat is said to miss stays when it fails to go about and so remains on its original tack.

Mizzen - The aftermost mast of a two masted vessel; on a vessel with three or more masts, the third mast from the bow; the sail set on a mizzen mast.

Mooring - Commonly, the anchor, chain, buoy, pennant, etc., by which a boat is permanently anchored in one location.

Motor well - An enclosure with watertight sides in which an outboard motor is mounted.

Moulded hull - A hull made of GRP or built up by bonding layers of marine ply.


Narrows - A narrow channel.

Nautical almanac - A book, published annually, containing navigational, tidal, astronomical and other data of use to sailors and navigators.

Nautical mile - A unit - of length, used in navigation, equal to 1852 metres or 6076.103 feet (see also Knot).

Navigation lights - The identifying lights that vessels must show at night.

Neap tides - The tides that occur at around the first and last quarters of the moon, and have a relatively small range (see also Spring tides).

No-go zone - The area, about 45° to either side of the wind, into which a sailboat cannot sail without tacking.


Observed position - A vessel's position as obtained by direct observation of charted features (see also Dead reckoning, Fix).

Offshore - Away from the shore.

Offwind - Any point of sailing away from the wind.

On the wind - Sailing as close to the wind as the boat will lie with advantage.

One-design - A boat built and equipped to conform to strict rules, so that it is identical to all the other boats in its particular class.

Onshore - On or toward the land.

On the quarter - Something is said to be on the quarter when its bearing is 45° abaft of the beam of the boat (see also Quarter).

Outhaul - A rope used to tighten the foot of a sail by hauling the clew along the boom.

Overfall - A turbulent stretch of water resulting from currents flowing over an underwater ridge.

Overhang - The amount that the bow and stem of a boat extend beyond her waterline.


Painter - A line attached to the boss of a small boat for tying it up.

Palm - A piece of leather fitted over the hand, with an iron for the head of a needle to press against in sewing canvas. Also, the fluke of an anchor.

Part - To break a rope or chain.

Pay out - To case a line or chain.

Postage - Sailing from one port or place to another.

Pay-off - When a vessel's head falls off from the wind. To pay, to cover over with tar or pitch. To pay out, to slack

Pennant - A tapering or triangular flag.

Pilot - Someone authorized to navigate vessels in and out of a port, or through a channel; a book of sailing directions

Pintle - An upright pivot pin which forms a hinge on a rudder.

Pipe berth - A sleeping berth constructed of a metal pipe frame to which canvas is laced.

Pitch - The downward motion of a boat's bows as it plunges into the trench of a wave (see also Yaw) .

Pitchpole - To tumble stern-over-bow when upended by a wave.

Plane - A boat is said to plane when it lifts onto its bow wave and skims over the water rather than moving through it.

Plot - To mark a chart with bearings. directions and courses.

Pointing - Sailing as close to the wind as possible.

Points of sailing - The main angles to the wind on which a boat may sail.

Pontoon - A floating platform or walkway to which boats my be secured; a float supporting such a platform.

Pooped - Boarded from astern by a breaking wave.

Port - The left-hand side of a boat as seen when facing the bow.

Port tack - A boat is said to be on a port tack the wind is blowing over its port side see also Starboard tack).

Position line - A line on a chart along which a vessel's position lies.

Pound - To strike the waves with jarring force, a characteristic of some hulls.

Preventer - A line, tackle or stay that prevents unwanted movement of a mast or boom (see also Boom preventer).

Privileged Vessel - The ship or boat having the right of way in a meeting situation.

Prop walk - The tendency of a propeller to pull the stern of a vessel to one side.

Prow - The fore part of a vessel, including the bows.

Pulpit - A guard rail set around the bow or stern of a boat. That at the stern is also called the pushpit.

Purchase - A tackle or lever mechanism used for raising, moving or tightening things (see also Tackle)

Pushpit - A guard rail set around the stern of a boat (see also Pulpit)


Quarter - The part of a boat between the beam and the stern (see also On the quarter).

Quarter berth - A bunk under the side of the cockpit.

Quartering - With the wind or waves on the quarter of the boat.


Race - A rapid current, especially through a narrow channel.

Rafting - Tying two or more boats alongside each other.

Rail - Top of the bulwarks (topsides above the deck).

Raised deck - An elevation of the full width of the deck forward to provide cabin headroom below.

Rake - The rearward slope of a mast.

Range - The difference in water level between low and high tide.

Rating - A way of classifying boats of different types and sizes so that they can race on a handicap basis.

Ratlines - small lines fixed between adjacent shrouds to form steps.

Reach - To sail with the wind blowing approximately abeam; the stretch of water between two bends in a river.

Ready about - The order to stand by to tack ship

Reefing - Folding or rolling a sail to reduce its area.

Reef points - Short pieces of rope used to tie up the reefed part of a sail.

Reeve - To pass the end of a rope through the end of a block, or an aperture.

Rib - The part of a hull frame to which planking is fastened.

Ride - To lie at anchor; to ride out a storm when at sea is to wait for it to pass (see also A-hull, Lie).

Riding light - Air all-round white light displayed at night (usually on the forestay) by an anchored vessel. Also called an anchor light.

Rig - The arrangement of masts, spars and sails carried by a vessel.

Rigging - The ropes and wires on a boat that keep the mast or masts in place and work the sails (see also Running rigging, Standing rigging).

Roach - The curved part of a fore-and-aft sail, bounded by the leech, that projects behind an imaginary straight line from the clew to the head.

Rocker - A hull characteristic, low in the middle and sweeping upward at the ends.

Round bilge - Hull design with the bottom smoothly rounded from keel to topsides.

Round turn - Two full turns with a line around an object.

Round up - To head into the wind.

Rub rail - A moulding around the hull to prevent it from being damaged by rubbing against piles, piers. and other craft.

Rudder - A movable underwater vane at the stern of a vessel, used for steering.

Rudderpost - The aftermost timber of a boat.

Rules of the road - The International Regulations for Preventing Collisions at Sea.

Run - To sail with the wind aft or nearly aft.

Running lights - Navigation lights used while under way.

Running rigging - The sheets and - halyards that raise, lower and control the sails (see also Standing rigging).


Safety harness - A harness attached to a line secured to the boat, and worn by crew in bad weather.

Saloon - A cabin.

Sam(p)son post - A vertical wooden or metal post to which warps or cables may be secured.

Scantling - A term applied to any piece of timber, with regard to its breadth and thickness, when reduced to the standard size.

Schooner - A vessel with two or more masts (the aftermost of which is the main mast) and all lower sails rigged fore-and-aft.

Scupper - An opening let into the bulwarks of a vessel to allow deck water to drain away; to sink one's own vessel deliberately.

Sea anchor - A drogue deployed as a floating anchor to help a vessel ride out a gale or storm.

Sea breeze - A breeze blowing from the sea. It occurs mainly during the day, when the land is warmer than the sea (see also Land breeze).

Seacock - A valve in the hull of a vessel, below the waterline, for admitting seawater or pumping out bilge water.

Sea kindly - Performing well in rough water.

Seize - To fasten ropes together by turns of small stuff, to secure hooks, etc.

Self-bailing - Capable of draining any shipped water through scuppers, such as a self-bailing cockpit.

Set - The direction of a current.

Shackle - A U-shaped link, closed by a bolt or pin.

Shackle key - A metal tool for unscrewing shackle pins.

Shake - To loosen or cast off.

Shank - The main piece in an anchor; the stock is made fast at one end, and the arms at the other.

Sheave - A pulley wheel (see also Block).

Sheer - The deck line of a vessel, as seen from the side.

Sheet - The rope attached to the clew of a sail, with which the sail may be trimmed or tensioned.

Shift - Change in direction of the wind.

Shock cord - A strong, elasticised rope.

Shore - A prop or stanchion, placed under a beam. To shore, to prop up.

Short board - Same as a short tack or leg. A long board is a long tack.

Shorten - One shortens sail when he takes in canvas to reduce the area of sail set.

Shrouds - Wires fixed at each side of a mast to support it (see also Standing rigging, Stays).

Shy - Term usually refers to spinnaker set with pole rigged forward for a reaching breeze. -

Side lights - The red (port) and green (starboard) lights that a vessel must show at night.

Skeg - Timbers used to deepen the after part of a keel, or a metal or wood extension of the keel protecting the propeller, and often supporting the rudder.

Slack tide - The short period at high or low tide when there is no tidal flow. Also called slack water.

Slip - To release or let go, for instance to slip anchor.

Sloop - A single-masted boat, Bermudan-rigged or gaff-rigged, with a single headsail.

Slot - Space between leeward side of mainsail and the windward side of jib.

Snatch block - A block into which a rope can be inserted quickly from the side instead of being threaded through.

Snub - To check the movement of a line by taking a turn around bitts, a snubbing winch, a cleat or a post.

Sole - Floorboards.

Sound - To measure the depth of the water; a relatively narrow stretch of water linking two larger areas; an inlet or deep bay.

Spars - A general term for the various pole-like pieces of gear on a boat, including masts, booms and gaffs.

Spinnaker - A sail of light material and large area, hoisted to the masthead and encircling the bow beyond the headstay, poled out opposite the mainsail, and sheeted in on the other side; controlled by a guy to the pole and sheet to the clew; it is used for running and broad reaching.

Spit - A thin strip of sand or shingle projecting from the shore.

Spitfire jib - A small storm jib of heavy canvas.

Splicing - joining two ropes by intertwining their strands.

Spray rails - Narrow timbers fastened to the planking to divert and flatten spray, thus keep it from coming aboard.

Spreaders - Struts on each side of a mast to increase the spread and holding power of the main shrouds. Also called cross-trees.

Spring - A mooring line led forward from the stern or aft from the bow.

Spring tides - The tides that occur at or near full and new moon, and are the lowest low tides and the highest high tides (see also Neap tides).

Sprit - A spar extending from the mast to the peak of a four-cornered sail.

Square-rigger - A ship rigged with four-sided sails hung on yards athwart (across) the ship.

Stanchions - The upright posts that support the guardrails and lifelines.

Standing - The standing part of a rope is that which is fast, the opposite to the hauling part. The standing part of a tackle is that part which is made fast to the blocks and between that and the next sheave, the opposite to the hauling and leading parts.

Standing rigging - The shrouds and stays that support the mast or masts (see also Running rigging).

Stand on - To maintain course.

Starboard - The right-hand side of a boat as seen when facing the bow.

Starboard tack - A boat is said to be on a starboard tack when the wind is blowing over its starboard side (see also Port tack).

Start - A sheet is started when it is eased off.

Stays - Wires fixed fore and aft of a mast to support it (see also Shrouds, Standing rigging).

Staysail - An auxiliary sail, usually triangular, attached to a forestay.

Steerageway - A boat is said to have steerageway when it is moving fast enough to allow it to be steered.

Stem - The main timber or structure at the bow of a boat; the foremost end of a boat, as in the phrase 'from stem to stern' (see also Stern post).

Step - The fixture into which the heel of a mast is fitted.

Stern - The after (rear) part of a vessel.

Stern post - The main timber or structure at the stern of a boat (see also Stem).

Stiff - A vessel is said to be stiff if it is relatively resistant to heeling or rolling, and returns quickly to the vertical (see also Tender).

Stock - The part of a rudder to which the tiller is fitted.

Stop - A block of wood secured to the keel, into which the heel of the mast is pieced.

Stow - To pack away.

Stringer - A fore-and-aft (longitudinal) structural timber in the framing of a hull.

Surge - A large, swelling wave. To surge a rope or cable, is to slack it off suddenly from a cleat or winch.

Swinging straps - Straps in a sailing dinghy under which the feet of the crew may be hooked, allowing him to swing his body out over the side of the boat. -


Tack - The forward lower corner of a fore-and-aft sail; to turn the bows of a boat through the wind; to sail a zigzag upwind course by repeated tacking; to sail with the wind blowing from forward of the beam (see also Port tack, Starboard tack).

Tackle - A rope and block purchase system (see also Block, Purchase). -

Take up - To tighten.

Tail - A rope spliced onto the end of a wire halyard or brace.

Tail off - To pick up the end of a line around a winch and haul on it.

Tangs - The metal fittings that secure the shrouds and stays to the mast.

Tell-tales - Small lengths of wool sewn to each side of a sail to indicate the airflow over it.

Tender - A small boat towed or carried by a larger vessel and used to ferry people and stores between the larger vessel and the shore; a boat is said to be tender if it is easily heeled over by the wind (see also Stiff)

Tender - Easily heeled.

Thimble - A brass eyelet let into the corner or along the edge of a sail or canvas cover.

Thwart - A seat running across a dinghy or other small boat.

Tide - The regular rise and fall of sea level caused by the gravitational pull of the sun and the moon; the horizontal flow of water resulting from these changes in sea level.

Tide rode - A moored or anchored boat is said to be tide rode when it has swung round so that its bows are facing into the incoming or outgoing tide (see also Wind rode).

Tiller - A wooden or metal handle attached to the top of a rudder and used to control it.

Toe straps - Loops into which dinghy crews can put their feet to keep them secure when sitting out.

Toe rail - The vertical rail section at the periphery of a weather deck.

Tong - A metal fitting on a mast to which a stay is attached.

Topping lift - A rope or tackle that supports the end of a boom.

Topsides - Sides of the vessel between the waterline and the rail.

Track - The intended course of a vessel.

Transit - Two objects are said to be in transit when, from the point of view of an observer, they are directly in line with each other.

Transom - The stern surface of a vessel.

Transom knees - Knees bolted to the transoms and after timbers.

Trapeze - A support used by the crew (and sometimes the helmsman) of a racing dinghy to place his or her weight outside the boat.

Traveller - A sliding fixture, travelling on - a track, to which a sheet is attached so that its angle can be altered.

Trim - The fore-and-aft inclination of a boat; to change or adjust the set of a sail.

Trip - To raise an anchor clear of the bottom. To release a spring-loaded snap-shackle as used on spinnaker poles, sheets and braces.

Trough - The hollow between crests of waves.

Trunk cabin - A cabin extended above a deck by means of a trunk housing around the deck opening.

True wind - The actual speed and direction of the wind, rather than the apparent wind as perceived on a moving boat (see also Apparent wind).

Trysail - A loose-footed, triangular sail used in place of the mainsail in heavy weather.

Turn - Passing a rope around a pin or cleat, to keep it fast.


Una rig - Having only one sail.

Unbend - To cast off or to untie.

Under way - On the move.

Unreeve - To pull a rope clear of a block.

Unship - To remove (as an oar, tiller or rudder) from its proper position.

Upwind - To windward.

Uphaul - A rope or tackle used to haul up a sail (such as a spinnaker) (see also Downhaul).


Vang - A rope used to support a gaff or sprit (see also Boom vang).

V-bottom - A hull with bilges forming a V-section from chines to keel.


Wake - The track or path a vessel leaves behind her when sailing.

Wake course - The course actually travelled by a vessel.

Warp - A rope used to secure or move a vessel; to move a vessel by hauling it with ropes.

Watch - A division of time on board ship.

Waterlines - Horizontal sections of a hull, parallel with the waterline.

Way - Movement of a vessel through the water.

Weather - The area upwind (to windward) of a boat or other object (see also Lee).

Weather side - The upwind (windward) side of a boat or other object (see also Lee side).

Weather tide - A tide running against the wind (see also Lee tide).

Weigh anchor - To lift the anchor off the bottom.

Wetted surface - The total submerged area of a hull.

Whip - A purchase formed by a rope rove through a single block. Also to secure the end of a rope from fagging by seizing of twine.

Whipping - Binding the end of a rope to stop it fraying.

Whisker pole - A pole used as a boom for the jib when sailing goose-winged (see also Goose-winged)

Winch - A hand-operated or powered machine for hauling in sheets or halyards.

Wind rode - A moored or anchored boat is said to be wind rode when it has swung round so that its bows are facing into the wind (see also Tide rode).

Windward - Upwind; toward the weather side; the direction from - which the wind is blowing (see also Leeward).

Work - A vessel works when otherwise rigid members of the construction loosen up. She works to windward when gaining ground against the wind by successive tacks.


Yacht - A vessel of recreation or state.

Yard - A spar suspended from a mast to spread a sail.

Yaw - The sideways motion of a boat's bows as it plunges through waves (see also Pitch).

Yawl - A two-masted vessel, rigged fore-and-aft, with a large main mast and a small mizzen (rear) mast stepped just aft of the rudderpost.

basic sailing terms and phrases and nautical terms and phrases