Below is a list of some useful nautical terms.


ABOARD - On or within the boat.


ADRIFT - Loose, not on moorings or towline.


AFT - Towards the stern of the boat.


AHEAD - In a forward direction.


ASTERN - In back of the boat, opposite of ahead.


BATTEN DOWN - Secure hatches and loose objects both within the hull and on deck.


BOW - The forward part of a boat.


BOWLINE - A knot used to form a temporary loop in the end of a line.


BRIDGE - The location from which a vessel is steered and its speed controlled. 




BULKHEAD - A vertical partition separating compartments.


BUOY - An anchored float used for marking a position on the water or a hazard and for mooring.


CABIN - A compartment for passengers or crew.


CAPSIZE - To turn over.


CAST OFF - To let go.


CATAMARAN - A twin-hulled boat, with hulls side by side.


CHART - A map for use by navigators.


CLEAT - A fitting to which lines are secured. 


COURSE - The direction in which a boat is steered.


CURRENT - The horizontal movement of water.


DEAD AHEAD - Directly ahead.


DEAD ASTERN - Directly aft.


DINGHY - A small open boat.


FENDER - A cushion, placed between boats, or between a boat and a pier, to prevent damage.


FLARE - A distress signal.


FLOOD - A incoming current.


FORWARD - Toward the bow of the boat.


GUNWALE - Upper edge of a boat's sides.


HATCH - An opening in a boat's deck fitted with a watertight cover.


HEAD - A toilet on a vessel. 


HEADING - The direction in which a vessel's bow points at any given time.


HULL - The main body of a vessel.


KEEL - The centerline of a boat running fore and aft.


KNOT - A measure of speed equal to one nautical mile (1,852m) per hour.


LATITUDE - The distance north or south of the equator measured and expressed in degrees.


LINE - Rope used aboard a vessel.


LONGITUDE - The distance in degrees east or west of the meridian at Greenwich, England.


MARLINSPIKE - A tool for opening the strands of a rope while splicing.


NAUTICAL MILE - One minute of latitude; approximately 1,852m - about 1/8 longer than the statute mile of 1,600m.


OVERBOARD - Over the side or out of the boat.


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-hand-side of a boat.


RUDDER - A vertical plate or board for steering a boat.


SQUALL - A sudden, violent wind often accompanied by rain.


STARBOARD - The right-hand-side of a boat when looking forward.


STERN - The rear part of the boat.


TIDE - The periodic rise and fall of water level of a body of water due to the gravitational pull of the moon.


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.


TRIM - Fore and aft balance of a boat.


UNDERWAY - When a vessel is in motion i.e. not moored.


WAKE - Moving waves, track or path that a boat leaves behind it, when moving across water.


WINDWARD - Toward the direction from which the wind is coming.