Glossary of boating terms

The Glossary of nautical terms below is assist clients when reading surveys in to the meaning of some of the nautical terms used within the text of survey reports.  The list is continually evolving and any suggestions to additions would be welcome.


Abaft  Rear of any particular point on the vessel. E.g. abaft the mast – behind the mast.
Abeam A point that is at right angles to the line of the keel.
Aft The rear of the vessel or face to the rear
Amidships Midway between the back and front of a vessel
Athwart Across or from side to side of a vessel
Awash A point where water constantly washes over it.
Backstay The standing rigging from the top of a mast to the back of the vessel to resist forward strain on the mast.
Ballast Weight placed in the keel of a ship to increase her stability often Iron or lead.
Battens Thin pieces of wood or fiberglass set into the leech of the sail to control shape.
Beam A) The wides point of a vessel. B) A timber across the vessel on which the deck is laid.
Becket An eye for attaching a rope too normally found attached to a block and tackle.
Belay To make a rope fast to a belaying pin or cleat.
Bight   A) Any part of a rope between its ends (B) A curve (C) a cove on a coastline or channel.
Binnacle The box which houses the compass and steering wheel.
Bitter end The last part of a achor cable/rope that is attached to the vessel when the rest is deployed overboard.
Bobstay A stay for the bowspirit to prevent it lifting mounted from bowspirit end to vessels stem at the waterline.
Bollard Heavy short post to secure ship’s mooring lines to.
Bolt rope A strong rope sewn round the edge of sails to give strength from tearing and to locate into a groove up a mast .
Boom A spar to stretch out the foot of a main sail.
Boot top A band of paint at the waterline between wind and water line.
Bower anchor Main anchor carried on a vessel.
Bow Forward section of a vessel.
Bowspirit Heavy spar from deck leading forward from stem head, to which headsails are attached.
Bridle  A rope attached to both sides of a boat or object to lift it. Lifting tackle or towing tackle.
Broach An accidentally turn that places the vessel broadside to the wind and sea.
Bulkheads Partitions fore and aft or Athwartships, forming separate compartments.
Bulwarks A vessel’s topsides that extend above the deck.
Cable  A) 1/10 Nautical mile, B) anchor chain, C) stainless steel wire.
Capstan A vertical cylindrical machine for hoisting the anchor chain/line.
Carvel Given to the planking for a vessels hull where the planks are laid edge to edge
Cathead A heavy piece of curved timber projecting from the bow of a ship for the purpose of holding anchors.
Caulking A term to discribe the filling material used to fill the gaps between a vessels side or deck planking seams to prevent leaking.
Cavitation The loss of effective propeller thrust caused by the blades of a propeller sucking air across the blades of the propeller instead of working within water.
Chain plates Metal strips fastened outside or inside the hull to attach standing rigging too.
Chine The fore and aft line of the hull where the bilge turns up towards the topsides of the hull.
Cleat A T shaped device attached to the vessel for making ropes fast to.
Clew The corner of the sail where the leech meets the foot.
Composite Construction method for a vessel built with a variety of materials.
Counter The overhanging portion of a stern.
Cradle The frame erected round and under a vessel to support her out of the water.
Cringle A round metal thimble mounted within a sail to pass ropes through the sail.
Crown A) Where the arms of an anchor meet the shank, B) the knot when the strands of a rope are interlocked to start a backsplice.
Crutch Fitting to support boom.
Davit Crane for hoisting, lowering and holding dinghys in position on a larger vessel.
Displacement Total weight of vesselalso known as Deadweight.
Deckhead Underside of a deck. The roof of a vessels cabin.
Downhaul Rope or tackle used to haul down sail or spar.
Draft The depth of water occupied by a vessel when afloat.
Drogue A sea anchor – a cone shaped canvas bag to which the vessel lies in heavy weather to keep the bow pointing into the waves, or towed from the stern to slow the speed when running.
Ensign The flag, usually carried at the stern, that denotes a vessel’s nationality.
Fairlead A fitting for leading a rope over an obstruction to avoid friction.
Fathom A measurement of depth. In units of six feet or 1.83m
Fender Soft rubber or other material to prevent chafe between the vessels side and another vessel and quay.
Fiddle A wooden lip to a table to keep objects from sliding off the table in rough waether.
Flare A)The outward spread of a vessel’s topsides B)A distress signal
Foot The lower edge of a sail.
Fore and Aft A term used to discribe the lengthways of a vessel.
Forward Towards the bow of a vessel.
Furl Gathering in sail and securing to a spar.
Gaff The spar to which the head of a fore and aft sail is attached to.
Galley The kitchen of a vessel of any size.
Gallows Frame of wood or metal with rounded top for supporting the boom.
Gimbals Swivels that hold a compass or stove horizontal at all times when a vessel is at sea.
Goose-neck A metal fitting for securing a boom to a mast. Allows for swing from side to sode and lifting.
GPS Global Positioning System
Gunwale The heavy top rail of at the top of a vessels topsides.
Guy A rope or wire used to control a spar or boom. 
Halyards Ropes or tackle used to hoist pennants or sails up the mast.
Hanks Strong clip hooks which attach head sails to the mast stays.
Hawse pipe A pipe leading down through the foredeck through which anchor chain is  led to the storage locker below.
Hawser A heavy rope used for mooring, kedging, lineing, towing or as a temporary anchor line.
Head board A triangular board sewn into the top of a sail, to which the halyard is attached.
Heads A vessels toilets.
Heaving line Light line, knotted on end to throw ashore when berthing, as a messenger for a larger mooring line.
Heel A vessel list sideways from the upright.
Helm The steering mechanism of a vessel (Tiller or Wheel)
Holiday An unpainted or unvarnished spot in a vessel.
Hounds A band around or attacment on the mast where lower stays or spreaders attach to the mast. 
Hull Structure of a vessel below deck level.
Jack Stay A bar or rope on which anything travels e.g. a rope leading along the deck, to which safety harnesses may be clipped.
Jack staff Small staff from which the vessels national flag is flown.
Jib The triangular sail set as the forward headsail.
Jury Rig After losing mast or rudder, makeshift rig to get the vessel to safety.
Kedge Anchor A lightweight anchor for kedging or moving the vessel by pulling up to it.
Keel The lower structural backbone of a vessels hull, often seperate unit   bolted to the hull in a modern yacht or intergal in older vessels.  
King spoke The spoke of the steering wheel which is upright when the rudder is centred.
Knot Measurement of speed and distance. One nautical mile per hour.
Lapstrake  Planking when one edge overlaps the other lower plank. (Clinker)
Launch To slide or lift a vessel into the water
Leech  The rear edge of a fore and aft set sail.
Leeward Direction away from the wind (loo’ard).
Leeway The sideways drift of a vessel from her course to leeward, due to wind pressure.
Life line Line stretched fore and aft for crew to hold on to.
List When a vessel heels to one side through having greater a weight on one side when at rest.
Log An instrument for recording the distance travelled through water.
Lubber line Line on the inside of a compass bowl indicating the ships heading.
Luff The forward edge of a sail
Marline spike  Pointed steel tool for opening strand of rope when splicing.
Mast head rig When the forestay is rigged to the top of a mast.
Messenger Line A thin line used to draw through another larger line through a mast or confined space. 
Midships To put the rudder fore and aft position.
Moor To attach the vessel to a dock or fixed bouy with lines.
Pintle A vertical pin on which the rudder is hung.
Pitching A vessels movement in at sea in a fore and aft direction.
Pooped A term to indicate that a heavy sea has come inboard over the stern.
Port The left hand side of a ship looking forward.
Ports /Porthole Watertight window in the ships side or superstructure for ventilation and light.
Rake The inclination of the mast in the fore and aft line from the vertical.
Reefing To reduce sail area.
Running rigging Ropes that move through blocks generally used to control spars and sails.
Samson post A large post on the foredeck used to secure an anchor or tow line too.
Scantlings The dimensions of a ship’s timbers.
Sheer The rise of a ship’s deck towards the bow or stern from amidships.
Sheer strake The upper line of plating or planking on the hull.
Sheet Rope attached to lower corner of sail for regulating its tension.
Shroud Standing rigging that supports a mast athwartships.
Skeg A fixed vertical fin attached to the hull on the after side of which the rudder is attached.
Sole The floor of a cabin or cockpit.
Sounder An electrical instrument to measure the depth of water.
Spring A mooring rope to prevent a vessel moving fore and aft when tied up.
Standing rigging Stationary rigging that supports a mast.
Starboard The right hand side of a ship facing forward.
Stem The forward plank or section of the hull from keel to the deck.
Stern post The aft plank or section of the hull from keel to the transom.
Tabernacle  A box like structure mounted on deck to hold the foot of the mast usually opening aft to allow mast to be lowered.
Tackle A purchase of ropes and blocks.
Taff-rail A rail around stern of vessel.
Thwarts Planks placed across the boat to form seats.
Tiller A lever for turning the rudder.
Transom The flat stern of a yacht, originally a board to which the after ends of planking was secured to.
Traveller A metal track with a car running athwartships to allow the main sheet to be trimmed on either side.
Tumble home Where a vessel’s sides are inclined inwards above the water line.
Turnbuckle A screw fitting for adjusting the tension of shrouds and stays.
Vang A block and tackle or strut for steadying a boom in a vertical orientation
Weather helm A boat has weather helm when it has a tendency to turn up into the wind under sail.
Windward Direction toward the wind.