abeam:

a direction at right angles to the centerline of the boat.

about, coming, or going:

changing direction by crossing the wind bow-first.

aft:

the back part of/or to the rear of a boat.

aloft:

at or toward the upper rigging.

amidships:

in or near the middle of a boat, either along the longitudinal axis or from side to side.

astern:

in the direction of, or behind, the stern.

auxiliary:

a boat designed primarily for sailing, but with a supplementary inboard engine.

back:

the wind is said to back when it changes in a counterclockwise direction, as from northeast to northwest. The opposite is to veer.

backstay:

any single wire supporting the mast from the stern.

bale:

a fitting on the end of a spar, such as the boom, to which a line may be fed.

bailers:

openings in the bottom or transom of a boat to drain water when sailing.

barber hauler:

a line attached to the jib or jib sheet, used to adjust the angle of sheeting by pulling the sheet toward the centerline of the boat.

battens:

flexible strips of wood or plastic, most commonly used in the mainsail to support the aft portion, or roach, so that it will not curl

flexible strips of wood or fiberglass placed in a sail to help the leech retain its proper shape.

beam:

measurement of the width of the boat

the width of the boat at its widest part. A boat is "on her beam ends" when heeled over 90 degrees.

bear:

to lie in a specified direction from a designated reference point; also, to move or tend to move in a certain direction.

bearing:

a direction

the direction in which an object is seen, or the direction of one object from another, expressed in compass points or degrees. A true bearing is one expressed in degrees relative to true north; a magnetic bearing is one expressed in degrees relative to magnetic north.

beat:

to go to windward in a sailboat by sailing alternate legs, with the wind first on one side and then on the other.

beating:

sailing against the wind by tacking

(close hauled, on the wind): sailing toward the wind source, or against the wind, with the sails pulled in all the way, tacking as you go, to reach a destination upwind.

becket:

a loop, eye or grommet; the eye in the strap of a block to which a line can be attached.

belay:

make a line fast

to make secure

to secure a line, usually to a cleat.

bend on:

tie or fasten.

bight:

a loop in a rope-or-a bend in the shoreline.

bilge:

curved part of the hull beneath the waterline, inside or out

a rounding of the hull along the length of the boat where the bottom meets the side

the lowest part of a boat, designed to collect water that enters the boat

binnacle:

container for ship's compass

compass stand.

bitt:

a single or double post fixed on a deck for securing mooring lines and towlines. On a deck, a bitt is more commonly called a bollard.

block:

a pulley

a wood or metal shell enclosing one or more sheaves, through which lines are led.

blue water sailing:

open ocean sailing, as opposed to being in a lake or sound.

boat hook:

a device designed to catch a line when coming alongside a pier or mooring.

bobstay:

wire stay underneath the bowsprit; helps to counteract the upward pull exerted by the forestay.

bollard:

a strong metal or wood post on a pier or towboat used to secure docking and towing lines.

bone in her teeth:

a colloquial phrase implying that a boat is moving through the water at considerable speed. The "bone" is the bow wave thus produced.

boom:

spar that takes the foot of a sail

the horizontal spar to which the foot of a sail is attached.

boom crutch:

support for the boom, holding it up and out of the way when the boat is anchored or moored. Unlike a gallows frame, a crutch is stowed when boat is sailing.

boomkin:

a device extending from the stern-somewhat as a bowspit extends from the bow-that carries a sheet block for the mizzen.

boom vang:

a system used to hold the boom down, particularly when boat is sailing downwind, so that the mainsail area facing the wind is kept to a maximum. Frequently extends from the boom to a location near the base of the mast. Usually tackle-or-lever-operated.

bow:

front end of a boat.

bowspit:

spar projecting from the bow

a short spar extending forward from the bow. Normally used to anchor the forestay.

braided line:

a line in which the strands are woven together, rather than twisted or laid up. Working lines are usually double braided, i.e., make up of two individually braided components, one inside for a core and a second outside for a cover.

bridge deck:

the transverse partition between the cockpit and the cab in.

bridle:

a short length of wire with a line attached at the midpoint. A bridle is used to distribute the load of the attached line. Often used as boom travelers and for spinnaker down hauls.

bright work:

varnished woodwork or polished metal.

broach:

turn sideways to wind and wave

a turning or swinging of the boat that puts the beam against the waves, creating a danger of swamping or capsize.

bulkhead:

an interior partition commonly used to stiffen the hull. May be watertight.

bullseye:

A round eye through which a line is led, usually in order to change the direction of pull.

bulwark:

a vertical extension above the deck designed to keep water out and to assist in keeping people in.

bulwarks:

rail around the deck.

buoy:

a float moored in water to mark a location, warn of danger, or indicate a navigational channel.

by the lee:

sailing downwind with the wind blowing over the leeward side of the boat, increasing the possibility of an unexpected jibe.

cabin sole:

the bottom surface of the enclosed space under the deck of a boat.

cabin trunk:

a structure built up above the deck and providing headroom below.

cap:

a piece of trim, usually wood, used to cover and often decorate a portion of the boat, i.e., caprail.

cardinal mark:

a navigation aid-used in the Uniform State Waterway Marking System-that is color-coded to indicate the compass direction around which it should be passed. A red-topped cardinal mark may be passed to the south or west, a black-topped one to north or east.

cast off:

to let go mooring or docking lines; to remove the turns of a line from a cleat; to untie a knot.

caulk:

to make seams watertight by filling them with a waterproof compound or other material.

center of effort (CE):

a theoretical point on a boat's sail plan that represents the focus or center of the total forces of wind on the sails.

centerboard:

retractable keel to stop a boat's leeward drift

a board lowered through a slop in the centerline of the hull to reduce sideway skidding or leeway. Unlike a draggerboard, which lifts vertically, a centerboard pivots around around a pin, usually located in the forward top corner, and swings up and aft.

chafe:

damage to a line caused by rubbing against another object.

chafe gear:

gear used to prevent damage by rubbing.

chain plate:

metal fitting to hold the shrouds

the fitting used to attach stays to the hull.

chainplates:

metal plates bolted to the boat which standing rigging is attached to.

chart recorder:

a highly sensitive depth finder in which the readings are noted by stylus traces on moving tape, often used by fisherman to locate schools of fish.

chock:

a guide for an anchor, mooring or docking line, attached to the deck

a metal fitting, usually mounted on or in a boat's rail, to guide hawsers or lines for mooring or towing.

chocks:

a heavy metal fitting fixed to the deck of a ship through which a line for mooring, towing, or anchor rope is passed.

chronometer:

a highly accurate timepiece, set to Greenwich Mean Time and used for celestial navigation.

chute:

colloquial for spinnaker-a lightweight headsail set from a boat that is reaching or running before the wind.

cleat:

fitting to which a rope may be belayed

a two-horned fitting used to secure a line to the boat or mast.

clevis pin:

a small cylindrically shaped pin used to close shackles or outhaul fittings, or to fasten a turnbuckle to a chain plate.

clew:

the lower after corner of a sail, where the foot meets the leech.

close-hauled:

sailing close to the wind with sails pulled in.

clove hitch:

two half hitches.

clutter:

unwanted reflections on a radar screen, commonly from rain, snow or sleet.

coach roof (also trunk):

the cabin roof, raised above the deck to provide headroom in the cabin.

coaming:

a vertical extension above the deck to prevent water from entering the cockpit. May be broadened to provide a base for winches.

a raised framing around deck openings such as hatches or cockpits to keep water out.

cockpit:

the area, below deck level, that is somewhat more protected than the open deck, from which the tiller or wheel is handled.

companionway:

the main entrance to the cabin, usually including the steps down into the cabin

a passageway through which a ladder or stairs lead from the deck down to the cabin.

compass point:

one of 32 divisions of the compass card equal to an arc of 11 1/4 degrees. The cardinal points are north, east, south and west; the intercardinal points are northeast, southeast, southwest and northwest.

compass rose:

two concentric circles, each divided into 360 degrees or 32 points, printed on nautical charts and used for laying off courses or bearings. The outer circle is graduated in degrees true, the inner circle is degrees magnetic.

contour line:

a line on a chart connecting points of equal depth or elevation.

controlling depth:

the minimum depth of a specified channel.

counter:

at the stern of the boat, that portion of the hull emerging from below the water, and extending to the transom.

countercurrent:

a current flowing in a direction opposite to that of the principal current.

course:

compass heading or the angle of the boat in sailing against the wind

the direction in which a ship is steering in making her way from point to point during a voyage. A magnetic course is the direction of the ship's heading relative to magnetic north; a compass course is the direction of the ship's heading based on the ship's compass (including errors of deviation and variation).

cringle:

loop or eye on the edge of a sail.

cutter:

a sailboat with one mast stepped more than one third of the way aft, capable of carrying two or more sails ahead of the mast; also, a Coast Guard boat.