Abaft – Toward the stern.
Abeam - At right angles to or beside the boat
Aboard - On or in the boat
Absolute bearing – The bearing of an object in relation to north. Either true bearing, using the geographical or true north, or magnetic bearing, using magnetic north.
Aft – Towards the stern of a vessel.
Aground – Resting on the ground or bottom (usually involuntarily).
Aloft - overhead, above
Amidships - the middle of the boat (athwartships)
Anchor - An object designed to grip the ground, under a body of water, to hold a boat in a selected area
Apparent Wind - the direction of the wind relative to the speed and direction of the boat
Astern - behind the boat
Avast – Stop! Cease or desist!
Backstays – Lines or cables, reaching from the stern of the vessel to the mast head, to support the mast.
Baggywrinkle – A soft covering for cables (or any other obstructions) that prevents sail chafe.
Bailer – A device for removing water that has entered the boat.
Ballast - weight in the lower portion of a boat, designed to add stability
Battens - thin, stiffeners placed in pockets in the leech of a sail, to assist in keeping its form
Beam – A measurement athwartships of a vessel.
Beam reach - a point of sail where the boat is sailing at a right angle to the wind
Bearing - a compass direction from one point to another.
Belay – To make fast a line around a cleat or belaying pin.
Belaying Pin – Adjustable bars of iron, bronze or hardwood to which running rigging may be secured.
Bevel - A surface which has been angled to make a fit with another.
Bight - a loop of line or rope.
Bilge – The compartment at the lowest point of the hull of a ship or boat where water collects. Also the turn of the hull near the waterline in a round bottomed boat.
Bilge Keels – A pair of keels on either side of the hull, usually canted outward.
Binnacle – The stand on which a 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.
Blind Fastening - One in which the point of the nail does not protrude through the timber.
Block – A pulley
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Boat Hook - a device designed to catch a line or cleat when coming alongside a pier or mooring.
Bolt Rope - a rope sewn into the luff of a sail for use in attaching to the standing rigging.
Boom – A spar attached to the foot of a fore-and-aft sail.
Boom gallows – A raised cross member that supports a boom when the sail is lowered.
Boom Vang - a line that adjusts downward tension on the boom.
Bottom Boards - Lengths of timber fastened together and laid over the bottom of a boat or on top of frames (floors).
Bow – The forward end of a vessel.
Bowsprit – A spar projecting from the bow used as an attachment for the forestay and other rigging.
Breast line - a docking line approximately at a right angle from the boat to the dock.
Brightwork – Varnished wood on a boat.
Broaching - Accidentally swinging broadside on to the wind and sea when running free.
Broad Reach - A point of sail where the boat is sailing off the wind, but not directly downwind.
Buoy - an anchored float marking a position or for use as a mooring.
Bulkhead - Transverse structural member forming a compartment. Often in conjunction with a frame station.Buoy - an anchored float marking a position or for use as a mooring.
Bulwark - The extension of the vessel's side above the level of the weather deck.
By the Lee - sailing with the wind coming from behind.
Carvel Build - This term is sometimes taken to be synonymous with a skeleton build with flush-laid strakes. A form of boat building in which the strakes or planks are placed edge to edge so that they are flush with one another.
Can - A type of navigation buoy.
Capsize - To swamp or turn a boat over.
Cast Off - To release lines holding a boat to shore or mooring. To release sheets.
Caulk - To insert material between two members after they have been assembled, and thus make the junction watertight. (See luting.)
Centerboard — A board or plate lowered through the hull of a dinghy, at or near the centerline, to resist leeway.
Chafe - Damage to a line caused by rubbing against another object.
Chafing gear - Material applied to a line or spar to prevent or reduce chafing or wear. (See Baggywrinkle.)
Chine - Where the sides of a boat meet the bottom or two wide strakes join. A soft chine is when the strakes join at a wide angle, and hard chine is when they join at a tighter angle, such as in a flat bottomed boat.
Chine Log - Structural stringer notched into the frames to support a chine seam in a hard-chined boat.
Chock - a guide for an anchor, mooring or docking line, attached to the deck.
Chainplates - metal plates bolted to the boat that support standing rigging. (eg: shrouds and stays on a sailboat)
Clamp - Gripe. A device for holding elements of a boat together temporarily.
Clench - Rivet. To deform the end of a fastening so that it will not draw out - often done over a rove.
Cleat - (1) Support member for a join, such as fastening a thwart to a hull.
(2) Hardware for securing a line, such as a painter or sheet.
Clew - the lower aft corner of a sail, attachment point for the sheets.
Clinker Build - A form of boatbuilding in which the strakes are placed so that they partly overlap one another - upper strake outboard of lower strake. (see Lapstrake)
Close hauled - a point of sail where the boat is sailing as close to the wind as possible.
Close reach - a point of sail where the boat is sailing toward the wind but is not close hauled.
Coaming - The raised edge of a hatch, cockpit or skylight to deflect water.
Cockpit - The area towards the stern of a decked vessel that houses the rudder controls.
Construction Plan - A scale drawing of the boat with a longitudinal section, horizontal plan and several transverse sections. The position and nature of the scarfs and other important construction details and scantlings may also be given.
Cove - Scotia. A hollow shaped moulding. May be used to hold the luting between two strakes.
Crook - A curved piece of wood which has grown into a shape useful for boatbuilding.
Cuddy — A small cabin in a boat.
Cunt Splice or cut splice — A join between two lines, similar to an eye-splice, where each rope end is joined to the other.
Cuntline — The "valley" between the strands of a rope or cable. Before serving a section of laid rope to protect it from chafing, it may be "wormed" by laying yarns in the cuntlines, giving that section an even, cylindrical shape.
Daggerboard – A type of centerboard that is lifted vertically.
Deadeye - Wood turning block. Used for tensioning shrouds and rigging.
Deadwood - portion of skeg/keel that is not ballast in a ballasted keel.
Displacement - the weight of the amount of water displaced by a boat.
Dock - A structure designed to accommodate boats attached to a pier, also the act of approaching the pier to secure it.
Dolly - A metal billet held against the head of a boat nail while it is being clenched.
Double-ended - A boat which is (nearly) symmetrical about the transverse axis.
Downhaul - a line attached to the tack, that adjusts tension in the sail.
Draft - the depth of the boat at its lowest point. Also the depth or fullness of a sail.
Drift - the leeway or movement of a boat when not under power, or when pushed off-course while under power.
Ease - To loosen or let out. Slacken.
Fair - A line is fair when it has no abrupt changes of direction.
Fairlead - A fitting or block used to change the direction of a line.
Fathom - A measurement relating to the depth of water. One fathom equals six feet.
Feather-edge - Tapering to nothing, as in a scarph.
Floor - A transverse member - often a crook - extending from the turn of bilge to turn of bilge and set against the planking.
Frame - A transverse member made up of more than one piece of timber. Usually extending from sheer to sheer and set against the planking.
Foot - The bottom edge of a sail.
Forward - Toward the bow of a boat.
Foremast - The forward mast of a boat with more than one mast.
Foresail - A jib or similar triangular sail forward of the leading mast, attached to the bow. A headsail.
Fouled - Entangled or clogged.
Freeboard - the distance from the highest point of the hull to the water
Furl - To fold, roll or secure a sail.
Futtocks – Pieces of timber that make up a large transverse frame.
Garboard - The strake laid next to the keel or keel plank.
Gammon Iron – The bow fitting which clamps the bowsprit to the stem.
Genoa - A large triangular foresail that overlaps the mainsail on a fore and aft rigged sailboat.
Gimball - A device that suspends a compass so that it remains level regardless of boat movement.
Gooseneck - A device connecting a boom to a mast on a sailboat.
Ground Tackle - An anchor, chain and rode.
Gooseneck – Fitting that attaches the boom to the mast
Grommet - Strand(s) of rope laid up in the form of a ring.
Groggy – Drunk from having consumed a lot of grog.
Gudgeon – Rudder pivot. The gudgeon supports the pintle.
Gunwale - Gunnel. A longitudinal member fitted round the inside top edge of the sheer strake of an open boat.
Halyard - A line used to raise and lower a sail.
Handy Billy – A loose block and tackle with a hook or tail on each end, which can be used wherever it is needed. Usually made up of one single and one double block.
Hard A-Lee - The command given to inform the crew that the helm is being turned quickly to leeward, turning the boat windward. Helm down.
Head - The top of a sail. Attachment point for a halyard.
Head to Wind - The bow turned into the wind, sails luffing.
Headsail - A sail forward of the mast, a foresail.
Headstay - A wire or line attaching and supporting a mast to the bow.
Headway - Forward motion.
Heaving - Rising and falling as a whole with the seas.
Helmsman - The member of the crew responsible for steering.
Heel - The unbalance of a sailboat caused by the wind's action on the sails. Also an unbalance in a boat's trim due to uneven distribution of weight.
Hike - Leaning out over the side of a sailboat to balance it.
Hoist - To raise aloft.
Hawser - Large rope used for mooring or towing a vessel.
Head - The toilet or latrine of a vessel
Heave Down - Turn a ship on its side for repairs or cleaning.
Heave-To - To stop a boat and maintain position by balancing rudder and sail to prevent forward movement. Also "hove-to". See: In irons.
Heaving - Rising and falling as a whole with the seas.
Helm – The tiller, or other steering devise.
Hitch – A knot used to tie a rope or line to a fixed object.
Horn - To check the squareness of a mold, relative to the boat's centerline.
Horn Timber – A fore-and-aft structural member of the hull sloping up and aft from the keel to support the counter.
Horse – Attachment of sheets to deck of vessel (main-sheet horse).
Hounds – Attachments of stays to masts.
Hull – The shell and framework of the basic flotation-oriented part of a vessel.
Hull Speed – The maximum efficient speed of a displacement-hulled vessel.
In Irons – When the bow of a sailboat is headed into the wind and the boat has stalled and is unable to maneuver.
Jack - A sailor. Also jack tar or simply "tar".
Joggle - To cut out a notch in a piece of timber so that it will fit close against another member.
Jib – A triangular staysail at the front of a sailboat.
Jibe - A change of tack while going downwind where the stern of the boat moves through the eye of the wind.
Jury Rig – Both the act of rigging a temporary mast and sails and the name of the resulting rig.
Knot - A unit of speed, one knot = 6,076 feet per hour. See also: Nautical Mile.
Keel - The main longitudinal strength member, scarfed to the stempost forward and the sternpost or transom, aft.
Keelson - longitudinal structural member laid parallel to the keel, most often inside the planking.
Ketch - A two-masted ship with a mizzen mast mounted forward of the rudder post.
King Plank – The centerline plank of a laid deck. Its sides are often recessed, or nibbed, to take the ends of their parallel curved deck planks.
Knee – Connects two parts roughly at right angles, as with deck beams to frames.
Knighthead –
1. A mitred backing timber which extends the after line of the rabbet in the stem to give extra support to the ends of the planks and the bowsprit.
2. A bollard or bitt.
3. Either of two timbers rising from the keel of a sailing ship and supporting the inner end of the bowsprit.
Land - That part of a strake which is overlapped by the strake immediately above it.
Lanyard - A line attached to any object for the purpose of securing the object.
Lapstake - A form of boatbuilding in which the strakes are placed so that they partly overlap one another - upper strake outboard of lower strake. (see Clinker-build).
Larboard – port side or port, opposite of starboard. Left side of vessel while facing forward.
Lay-off - Lofting. To draw out the lines of a boat full size.
Lazarette – Small stowage locker at the aft end of a boat, often doubles as a seat.
Leeward - Downwind.
League – A unit of length equal to three nautical miles.
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.
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.
Leeboard – A fin mounted on the side of a boat (usually in pairs) that can be lowered on the lee side of the ship to reduce leeway (sim. to centerboard).
Leeway – The amount that a ship is blown leeward by the wind.
Leeward - In the direction that the wind is blowing towards.
Length Overall (LOA) – the length of a vessel.
Length on Waterline (LWL) - measurement of waterline. A waterline may be expressed as the load waterline or design waterline.
Lifeline - A cable fence that surrounds the deck to prevent crew from falling overboard.
Limber Holes - relief cut into a frame or floor to allow water to drain into the bilge.
Line – the nautical term for a majority of the cordage or "ropes" used on a vessel.
Lines - The interrelation of sections in different planes which show the shape of a boat's hull. They usually consist of (i) sheer plan with longitudinal sections, (ii) half breadth plan with waterlines or horizontal sections, (iii) body plan with transverse sections. Diagonal lines, longitudinal section lines on the half breadth plan, and waterlines on the sheer plan enable the three plans to be related to each other and checked for fairness. Lines converted to numbers are known as a Table of Offsets.
List - To lean a boat to one side or the other.
Lofting – The technique used to convert a scaled drawing to full size used in boat construction.
Loom - That part of an oar inboard of the point of pivot; it includes the grip. The section of an oar between the loom and the blade is called the shaft.
Luff - The forward edge of a sail. Also; Luffing - To spill wind from the forward edge of a sail.
Lugger – A ship rigged with lugsails.
Lugsail – A four-sided fore-and-aft sail supported by a spar along the head that is hung from the mast by a halyard.
Luting - Traditionally luting is a plastic substance such as paint used between two adjacent members. (See Caulk)
Mainsheet - The line that controls the boom on a sailboat.
Mast – A vertical pole on a ship which supports sails or rigging.
Mast Step - Fitting used to locate the heel of a mast.
Mizzen - The shorter mast aft of the mainmast on a ketch or yawl.
Mooring - A permanent attachment to the sea bottom, often with a buoy at the surface, used to hold a boat in a specific area.
Moisture Content - The weight of water in a specimen of wood expressed as a percentage of the weight of oven-dry wood. Thus this figure can be greater than 100%.
Molds - Transverse wooden patterns taking their shape from the body plan.
Moulding - A pattern or linear decoration cut into a length of timber.
Nautical Mile – A unit of length corresponding approximately to one minute of arc of latitude along any meridian. By international agreement it is exactly 1,852 meters.
Nettles - Lines tied through cringles at the reef points.
Nun - A type of navigational buoy.
Oakum – Material used for caulking hulls. Traditionally tarred hemp picked from old untwisted ropes.
Outhaul – A line used to control the shape of a sail, adjusting tension along the foot.
Painter - A line attached to the bow of a boat for the purpose of securing it to a dock or other object.
Parrel – A movable loop or collar used to fasten a yard or gaff to its respective mast.
Paying – Filling a seam (with caulking or pitch), lubricating the running rigging with slush.
Pennant – A long, thin triangular flag flown from the masthead of a ship.
Pinch - To sail as close as possible towards the wind.
Pine Tar - Used for protective coatings on cordage, oakum, and wood. When traditional standing rigging is wormed, parceled and served, a mixture of pine tar and varnish is used between the layers to protect the natural fibers. (see: Stockholm tar).
Pintle – The pin or bolt on which a ship's rudder pivots. The pintle rests in the gudgeon.
Pitching - Plunging and ascending, so that the bow and stern rise and fall alternately.
Pitchpoling - Accidentally tumbling stern-over-bow in a half-forward somersault.
Point - To turn closer towards the wind (point up).
Pooped – Swamped by a high, following sea.
Port - Larboard. (1) Portion of the vessel on the left hand, facing forward. (2) Wine for cooking, or drinking, when the whiskey runs out.
Port Tack - Sailing with the wind coming from the port side, with the boom on the starboard side.
Posh - (word history obscure) possibly an acronym for "Port Out Starboard Home" referring to British ships to and from India in the late19th century. POSH accommodations referred to the 'shady' (Port) side of the ship outbound and on the 'shady' (Starboard) side home-bound.
Preventer (gybe preventer, jibe preventer) – A sail control line on the boom leading to a fixed point on the boat's deck or rail, used to prevent or moderate the effects of an accidental jibe. Also vang.
Privileged Vessel - The ship or boat with the right-of-way.
Rabbet - Rabet. Rebate. A groove or channel worked in a member to accept another, without a lip being formed.
Ratlines – Rope ladders permanently rigged from bulwarks and tops to the mast to enable access to top masts and yards.
Rays - Layers of parenchyma cells in horizontal strands running out from the centre of a tree towards the circumference.
Reach - Sailing with a beam wind.
Ready About - prepare to tack (come about).
Reef - To reduce the area of a sail exposed to the wind
Reef Points – Attachment points for the nettles in a sail, which are used to secure excess fabric after reefing.
Rhumb Line - A straight line compass course between two points.
Rib - A simple form of frame. This term may be more appropriate than frame, when applied to small open boats.
Rigol – The rim or 'eyebrow' above a port-hole or scuttle.
Rigging - On a sailboat, standing rigging is the mast and support wires (eg. shrouds and stays), running rigging are the lines with which the sails are adjusted, (eg. sheets).
Rode – Anchor line, rope or cable.
Rolling - Inclining rhythmically from side to side.
Rove - Roove. A washer-like a piece of metal, which is forced over the point of a nail before it is clenched.
Rowlock – A bracket providing the fulcrum for an oar. (Also see: thole).
Rudder - Steering device mounted aft.
Running - A point of sail going directly downwind.
Scarf - Scarph. Scarve. A tapered or wedge shaped joint between pieces of similar section at the join.
Scull - (1) Feathering a rudder back and forth to move a boat forward. (2) Sculling: rowing with two oars.
Scupper – opening in bulwarks to drain water overboard.
Scuttle – A small opening in a ship's deck or hull.
Scuttlebutt –
1. A barrel holding water, that sailors would drink from.
2. Slang for gossip.
Seacock – a valve in the hull of a boat.
Shake - A crack or split forming in wood, usually during drying or seasoning. ie:
cup shakes - curved clefts between the growth rings
heart shakes - splits radiating from the center of tree
star shakes - splits forming in the shape of a star.
Shake Out - To release a reefed sail and hoist the sail aloft. (eg.: shake out a reef).
Shear - Sheer line. The curve of the upper edge of the hull.
Shear Strake - The top run of planking on a hull.
Shear Guard - Protective longitudinal rub-rail attached to the outside of the shear strake.
Sheave - The wheel of a block (pulley).
Sheet - A line used to control a sail.
Shell Construction - A method of boatbuilding in which the shell (ie the watertight envelope of stems, keel and planking) is built or partly built, before the ribs and other internal strengthening members are fitted.
Ship's Wheel – The usual steering device on larger vessels, connected to the rudder.
Shrouds - Wire(s) leading from the masthead to the sides of the boat to support the mast athwartships.
Skeleton Construction - A method of boatbuilding in which a framework of stems, keep and ribs is first erected. This skeleton is then covered by a "skin" of planking.
Skeg - Fore-and-aft "fin" attached to keel, appropriately ballasted.
Slush – Greasy substance obtained by boiling or scraping the fat from empty salted meat storage barrels. Used for greasing parts of the running rigging of a vessel.
Spanish Windlass - A simple rope and lever device for forcing two elements closer together and holding them there.
Spar – A wooden pole used to support various pieces of rigging and sails. Mast.
Splice – To join lines or cables by unraveling their ends and intertwining them to form a continuous line, eye or a knot.
Spile - To transfer an existing curved line onto a pattern for creating a matching plank or other wood shape.
Spinnaker - A large, lightweight sail used for downwind sailing.
Spreaders - Struts used to hold the shrouds away from the mast, forming a truss.
Spring Lines - Docking lines leading to or from the center of the shear that keep a boat from drifting forward and back.
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 – Permanent, fixed cable or line used to support masts and spars.
Station - The horizontal position of the transverse sections on the Lines. They are used as datum lines when building from drawings and molds are generally made of transverse sections at some or all of these stations.
Stay – Cable or rope running fore (forestay) and aft (backstay) from a mast to the hull.
Staysail - inner jib on a vessel with multiple headsails, hanked to the forestay. Often rigged with a self-tending boom.
Starboard - portion of the vessel on the right hand, facing forward.
Starboard Tack - A course with the wind coming from starboard and the boom on the port side.
Steering Oar or Steering Board – A long, flat board or oar hung from near the stern to steer a vessel. Predates the invention of the rudder. Traditionally on the starboard side of a boat (the "steering board" side).
Stem - structural member forming a fine end to a boat. A double-ended boat has two stems, fore and aft.
Step - A specific floor fitted to the keelson that accepts the base of the mast.
Sternpost - angled brace connecting transom and keelson. Preferably a natural grown crook.
Stockholm Tar - A blackish semi-liquid prepared by the destructive distillation of various trees of the Pinaceae family. (see: pine tar)
Stocks - Set-up. The temporary wooden support on which a boat is built.
Strake - A single plank or combination of planks which stretches from one end of a boat to the other.
Stern - the back of the boat.
Stow - to put away.
Stringer - A fore and aft structural member laid perpendicular to the frames.
Stretcher - An athwartships length of timber against which a rower braces his feet.
Surging - Being accelerated and decelerated by overtaking swells.
Swaying - Moving bodily sideways.
Tabernacle – A bracket attached through the deck, to which the foot of a mast is fixed. Two sides or cheeks with a through bolt form the pivot for raising and lowering the mast.
Tack - The forward, lower corner of the sail. Also, a course set with the wind coming from the side of the boat. To change course by turning into the wind so that the bow moves through the eye of the wind.
Tackle - Consists of a rope, or "fall" and blocks, through which the fall is "rove" (run). Used to gain purchase and increase mechanical pull, or change the direction of pull.
Template - A shaped pattern of an element or section of a boat made of plywood or hardboard, etc.
Tender - A small boat used to transport crew and equipment to and from shore for a larger boat.
Thole - A pin projecting upwards at sheer level to provide a pivot for an oar.
Thwart - A transverse member used as a seat.
Tiller – Lever used for steering, attached to the rudder post.
Timber - An element of a frame or rib. May also be used generally referring to any piece of wood used in boatbuilding.
Topping Lift - A line, leading from the top of the mast to hold up the boom when it is not being used, also a line that controls the height of a spinnaker pole.
Topsides – The portion of the hull between the waterline and the shear.
Transom - The squared-off end of a boat. A punt has two transoms, fore and aft.
Traveler - A track for a control sheet on a sailboat, allowing for fine tuning of sail shape.
Treenail - Trenail. Trunnel. Wooden peg or through-fastening used to join two members. It is secured at each or either end by the insertion of a wedge.
Trim - To adjust sails. Also the balance of a boat relative to the water.
Tumblehome – A hull shape, in transverse section, where the widest part of the hull is partway below deck level.
Tuning - The adjustment of standing rigging, sails and hull to balance a sailboat for optimum performance.
Vang - A rope leading from gaff, yard or boom to the deck, used to control "pumping" in the spar. (See preventer)
Wake - The swell caused by a boat passing through water.
Waterline - The line where the hull of a ship meets the surface of the water, in concept or reality. Specifically, it is also the name of a special marking, also known as an international load line, Plimsoll line and waterline.
Whisker Pole -A light spar which controls the clew of a jib when sailing downwind. Also referred to as a preventer.
Winch - A metal drum shaped device used for mechanical advantage in trimming sails.
Wheel - Propeller
Worm, Parcel and Serve – To protect a section of rope from chafing by laying yarns (worming) to fill in the cuntlines, wrapping canvas along the length (parceling) and seizing marline or other small stuff around it (serving).
Yankee Jib - A large jib set forward of a staysail in light winds.
Yard – The horizontal spar from which a square sail is suspended.
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Yawing - Lurching and changing direction to either side of a proper course.
Windward - Upwind; toward the wind.