ABAFT - Toward the rear (stern) of the boat. Behind.
ABEAM - At right angles to the keel of the boat, but not on the boat.
AFT - Toward the stern of the boat.
AGROUND - Touching or fast to the bottom.
ALEE - Away from the direction of the wind. Opposite of windward.
AMIDSHIPS - In or toward the center of the boat.
ASTERN - In back of the boat, opposite of ahead.
BEAM - The greatest width of the boat.
BEARING - The direction of an object expressed either as a true bearing as shown on the chart, or as a bearing relative to the heading of the boat.
BIGHT - The part of the rope or line, between the end and the standing part, on which a knot is formed.
BILGE - The interior of the hull below the floor boards.
BITTER END - The last part of a rope or chain. The inboard end of the anchor rode.
BOOT TOP - A painted line that indicates the designed waterline.
BOW - The forward part of a boat.
BRIDGE - The location from which a vessel is steered and its speed controlled. "Control Station" is really a more appropriate term for small craft.
BUOY - An anchored float used for marking a position on the water or a hazard or a shoal and for mooring.
CATAMARAN - A twin-hulled boat, with hulls side by side.
CHAFING GEAR - Tubing or cloth wrapping used to protect a line from chafing on a rough surface.
CHINE - The intersection of the bottom and sides of a flat or v-bottomed boat.
CHOCK - A fitting through which anchor or mooring lines are led. Usually U-shaped to reduce chafe.
CLEAT - A fitting to which lines are made fast. The classic cleat to which lines are belayed is approximately anvil-shaped.
COAMING - A vertical piece around the edge of a cockpit, hatch, etc. to prevent water on deck from running below.
COCKPIT - An opening in the deck from which the boat is handled.
CUDDY - A small shelter cabin in a boat.
DINGHY - A small open boat. A dinghy is often used as a tender for a larger craft.
DISPLACEMENT - The weight of water displaced by a floating vessel, thus, a boat's weight.
DISPLACEMENT HULL - A type of hull that plows through the water, displacing a weight of water equal to its own weight, even when more power is added.
DRAFT - The depth of water a boat draws.
EBB - A receding current.
FATHOM - Six feet.
FENDER - A cushion, placed between boats, or between a boat and a pier, to prevent damage.
FLOOD - A incoming current.
FOLLOWING SEA - An overtaking sea that comes from astern.
FOREPEAK - A compartment in the bow of a small boat.
FREEBOARD - The minimum vertical distance from the surface of the water to the gunwale.
GALLEY - The kitchen area of a boat.
GANGWAY - The area of a ship's side where people board and disembark.
GROUND TACKLE - A collective term for the anchor and its associated gear.
GUNWALE - The upper edge of a boat's sides.
HARD CHINE - An abrupt intersection between the hull side and the hull bottom of a boat so constructed.
HEAD - A marine toilet. Also the upper corner of a triangular sail.
HELM - The wheel or tiller controlling the rudder.
HULL - The main body of a vessel.
INBOARD - More toward the center of a vessel; inside; a motor fitted inside a boat.
INTRACOASTAL WATERWAY - ICW: bays, rivers, and canals along the coasts (such as the Atlantic and Gulf of Mexico coasts), connected so that vessels may travel without going into the sea.
JACOBS LADDER - A rope ladder, lowered from the deck, as when pilots or passengers come aboard.
JETTY - A structure, usually masonry, projecting out from the shore; a jetty may protect a harbor entrance.
KEEL - The centerline of a boat running fore and aft; the backbone of a vessel.
KNOT - A measure of speed equal to one nautical mile (6076 feet) per hour.
LAZARETTE - A storage space in a boat's stern area.
LEE - The side sheltered from the wind.
LOG - A record of courses or operation. Also, a device to measure speed.
MARLINSPIKE - A tool for opening the strands of a rope while splicing.
MIDSHIP - Approximately in the location equally distant from the bow and stern.
MOORING - An arrangement for securing a boat to a mooring buoy or a pier.
NAUTICAL MILE - One minute of latitude; approximately 6076 feet - about 1/8 longer than the statute mile of 5280 feet.
PLANING - A boat is said to be planing when it is essentially moving over the top of the water rather than through the water.
PORT - The left side of a boat looking forward. A harbor.
QUARTERING SEA - Sea coming on a boat's quarter.
RODE - The anchor line and/or chain.
RUDDER - A vertical plate or board for steering a boat.
RUN - To allow a line to feed freely.
RUNNING LIGHTS - Lights required to be shown on boats underway between sundown and sunup.
SATELLITE NAVIGATION - A form of position finding using radio transmissions from satellites with sophisticated on-board automatic equipment.
SCOPE - Technically, the ratio of length of anchor rode in use to the vertical distance from the bow of the vessel to the bottom of the water. Usually six to seven to one for calm weather and more scope in storm conditions.
SCREW - A boat's propeller.
SCUPPERS - Drain holes on deck, in the toe rail, or in bulwarks or (with drain pipes) in the deck itself.
SEA COCK - A through hull valve, a shut off on a plumbing or drain pipe between the vessel's interior and the sea.
SEA ROOM - A safe distance from the shore or other hazards.
SEAWORTHY - A boat or a boat's gear able to meet the usual sea conditions.
SOLE - Cabin or saloon floor. Timber extensions on the bottom of the rudder. Also the molded fiberglass deck of a cockpit.
SOUNDING - A measurement of the depth of water.
SPRING LINE - A pivot line used in docking, undocking, or to prevent the boat from moving forward or astern while made fast to a dock.
SQUALL - A sudden, violent wind often accompanied by rain.
STARBOARD - The right side of a boat when looking forward.
STEM - The forward most part of the bow.
STERN - The after part of the boat.
THWARTSHIPS - At right angles to the centerline of the boat.
TILLER - A bar or handle for turning a boat's rudder or an outboard motor.
TRANSOM - The stern cross-section of a square sterned boat.
WAKE - Moving waves, track or path that a boat leaves behind it, when moving across the waters.
WATERLINE - A line painted on a hull which shows the point to which a boat sinks when it is properly trimmed (see BOOT TOP).
WAY - Movement of a vessel through the water such as headway, sternway or leeway.
WINDWARD - Toward the direction from which the wind is coming.
YACHT - A pleasure vessel, a pleasure boat; in American usage the idea of size and luxury is conveyed, either sail or power.
YAW - To swing or steer off course, as when running with a quartering sea.
