ABAFT - Behind, toward a vessel's stern.
ABEAM - Off the side, amidships, at right angles to the fore and aft line.
ADRIFT - Not made fast, floating loose, at mercy of wind and current.
AFT - At, near, or toward the stern.
AGROUND - Touching or stuck on the bottom.
AHEAD - In front of the vessel, forward; opposite of astern.
ALOFT - Above deck, usually in the rigging.
AMIDSHIPS - In or toward a boat's middle part, between the sides or between bow and stern.
ANCHOR - Device used to secure boat to bottom of body of water.
ASTERN - At any point behind the boat, backward.
ATHWART - At right angles to the fore-and-aft line of a vessel.
BACK - Change in direction of the wind in counterclockwise direction, see veer.
BACKSTAY - Part of the standing rigging, usually cable, that supports the mast from aft.
BALLAST - Extra weight carried low in a vessel to increase stability.
BATTEN - Stiffening strip placed in leech of sail. Also, a wooden strip fastened over seam to stop leakage.
BEACON - A marked post located on a shoal or bank to warn vessels of danger or to mark a channel. A signal mark on land; a light or radio signal.
BEAM - The extreme width of a vessel. A horizontal athwartship support for the deck.
BEAR OFF - Steer away from the wind, shore or any object.
BEARING - the angular direction in which an object is observed with respect to a reference direction or another object.
BELAY - Secure a line without a knot or hitch. Also, command to stop or cease action.
BELOW - Beneath the deck.
BEND - Secure a sail fast to a spar or stay. Also, know to secure a line to another line or object such as an anchor.
BIGHT - Open or closed loop in a line or rope.
BILGE - The lowest part of the ship's interior.
BITTER END - The inboard (free) end of a line or rope.
BOLLARD - Stout post on wharf or pier for securing mooring lines.
BOOM - Spar used to extend and control foot of fore-and-aft sail.
BOW - The forward part of a vessel.
BROACH - The turning of a boat broadside to the wind or waves, subjecting it to possible capsizing.
BULKHEAD - A vertical partition or wall.
BULWARK - Extension of topsides above deck.
CAPSIZE - To turn over, upset.
CAST OFF - To let go a line, as to cast off a bow line.
CENTERBOARD - A board that is lowered through a slot in the keep to reduce leeway.
CHINE - Intersection of sides and bottom of a boat.
CHOCK - A deck fitting to guide a line where it leaves the boat. Also a wedge or bracket to keep articles from shifting.
CLEAT - A fitting, secured to the deck, mast, or spar, having two projection horns to which lines are made fast.
CLEW - Aft, lower corner of a sail.
CLOSE HAULED - Sailing as directly into the wind as possible, also, on the wind.
COAMING - A raised section around a hatch or cockpit to keep out water.
COCKPIT - Well or sunken space in the deck.
COME ABOUT - - Significant course change in sailing to bring the bow through the wind or tack.
COMPASS ERROR - Combined effect of variation and deviation.
COURSE - Intended direction for a boat to be steered.
DECK - Horizontal covering resting on the deck beams of a vessel, the floor of any compartment.
DEVIATION - Disturbing effect of boat's magnetic field upon its compass.
DINGHY - A small open boat used as a lifeboat for a yacht.
DOCK - The area of water between two landing piers. Also used to denote a pier or wharf.
DRAFT - The depth a vessel sinks when afloat, as measured vertically from the water line to the lowest point.
DROGUE - Object streamed from boat to decrease speed, sea anchor.
FAIRLEAD - Fitting to route control lines or cables.
FAIRWAY - Marine thoroughfare.
FATHOM - A unit of length used in measuring water depth. One fathom is 6 feet.
FENDER - A protector hung over the side between the boat and a pier or another vessel.
FLARE - The outward curve of a vessel's side near the bow.
FLUKE - Flattened end of an anchor arm which bites into the ground.
FORE - Prefix denoting at, near, or towards the bow.
FOUL - Not clear, jammed.
FOUL GROUND - A place not suitable for anchoring.
FREEBOARD - Vertical distance from the lowest part of the deck (or flow-through point in transom) to waterline.
GAFF - Spar which supports the upper side of a fore-and-aft four-sided sail. Also, long-handed hook to bring fish aboard.
GAFF RIGGED - A sailboat whose principal sail is supported by a gaff.
GEAR - A general name for ropes, blocks, tackle and other equipment used with our aboard a boat.
GIVE-WAY BOAT - One that does not have the right-of-way and should avoid the stand-on boat.
GROUND TACKLE - An anchor and anchoring gear.
GUNWALE - The part of a vessel where hull and deck meet. (Pronounced "gun'l")
HALYARD - Line for hoisting sails or flags.
HATCH - A covered opening in the deck.
HEAD - A boat's toilet. Also the upper corner of a triangular sail. The foremost part of a vessel.
HEADING - Direction in which a boat is pointing at a given moment.
HEAVE - To throw, as to heave a line ashore. The rise and fall of a vessel in a seaway.
HEAVE TO - To bring a vessel to a position where she will maintain little or no headway, usually with the bow into the wind or nearly so.
HEEL - The leaning of a vessel to one side such as caused by the wind.
HELM - The apparatus by which a vessel is steered, including the rudder.
HULL - The main body of a vessel exclusive of spars and rigging.
JIB - Triangular sail set on a stay forward of the mast.
JIBE - Hanging sail from one side to another with wind astern.
KEEL - The main structural member of a hull (backbone): underwater extension of hull to increase lateral resistance and stability.
KNOT - A nautical mile-per-hour measure of speed. A nautical mile is approximately 6076 feed. (A stature mile is 5280 feet.) Also a means for joining two lines together or fastening a line to an object.
LEE SHORE - One onto which wind or current could force a boat.
LEE SIDE - The side opposite that from which the wind blows.
LEEWARD - Direction away from the wind: downwind. (Pronounced loo-rd.)
LEEWAY - Sidewise movement of a boat through the water, caused by wind or current.
LIE TO - See heave to.
LIST - The leaning of a vessel to one side caused by misplaced gear or shifting cargo.
LUFF - Forward edge of a fore-and-aft sail.
LUFFING - To luff or luff up is to head into the wind causing sails to flutter.
MAINSAIL - Boat's principal sail, set aft of mainmast.
MARLINESPIKE SEAMANSHIP - General knowledge of knots, bends, hitches, splices and care of rope.
NAUTICAL MILE - Unit of distance equal to 6076.1 feet.
OUTHAUL - Line or device used to tension the foot of a sail.
PAINTER - A line tied to the bow of a dinghy for towing or making fast.
PAY OUT - Slacken or let out line.
PENDANT - Short rope serving as an extension of a line, chain, cable with a descriptive name based on use, e.g. mooring pendant.
PENNANT - Emblematic flag.
PIER - A loading platform extending out from the shore.
PITCHPOLE - Capsize end over end.
PORT - The left side of a vessel, looking forward. A place in which a boat can find shelter. Also, an opening in the side of a vessel.
QUARTER - Afterpart of a vessel's side (port quarter, starboard quarter).
REACH - Point of sailing with wind near the beam.
RELATIVE BEARING - Direction of an object relative to a boat's heading.
SCOPE - The ratio of length of an anchor line to the depth of water. The "depth" includes the height of the chock above the water, sometimes thought of as the length of rode.
SCUPPER - An opening in a deck or cockpit permitting water to drain out.
SEA ANCHOR - Device used for slowing a boat down, drogue.
SHEET - Line used to position a sail relative to the wind.
SHROUD - Standing rigging that supports a mast laterally.
SKEG - An extension of the keep for protection of propeller and rudder.
SLACK WATER - Minimum velocity of tidal current, sometimes abbreviated "slack".
SPEED - Rate of motion.
STAND-ON BOAT - One that has the right of way and should maintain her course and speed.
STARBOARD - The right side of a vessel looking forward.
STAYS - Standing rigging that supports a mast fore and aft.
STEM - The leading edge of a vessel's hull.
STERN - The after end of a vessel.
SWAMP - To fill with water.
TOPSIDE - On or above a weather deck, a deck wholly exposed to the elements.
TOPSIDES - The sides of a vessel between the waterline and the deck.
TRANSOM - The athwartship portion of a hull at the stern.
TRIM - The longitudinal balance of a boat. If either the bow or the stern is depressed, the vessel is said to be down by the bow or down by the stern. Also, to adjust the set of a sail.
VEER - Wind veers when its direction changes clockwise.
WAKE - The disturbed water following a moving vessel.
WASH - The rush or sweeping of waves on a bank, shore or vessel.
WAY - Movement of a vessel through the water such as headway, sternway or leeway.
WHARF - Manmade structure parallel to the shoreline for loading, unloading or making fast.
WHIPPING - Method of binding the end of a rope with small twine.
WINDWARD - The direction from which the wind is blowing.
YAW - To swing off course, caused by the action of waves or poor steering.