Boating Terms

Boating Terminology

A-Z of Boating Terms and Definitions

Have you ever been stumped by an old boating term or phrase? Or, perhaps you’d just like to learn more boating lingo. Our comprehensive list of boating terminology will set you on the right course. Simply click on the letter of the alphabet that your search word begins with to fast track your boating definition search. Or, take your time to scroll down the page to review all the boating terms.

ABEAMAt right angles to the keel of the boat, but not on the boat.
ABOARDOn or within the boat.
ABOVE DECKOn the deck (not over it – see ALOFT)
ABREASTSide by side; by the side of.
ADRIFTLoose, not on moorings or towline.
AFTTowards the stern (rear) of the vessel.
AGROUNDTouching or fast to the bottom.
AHEADIn a forward direction.
AIDS TO NAVIGATIONArtificial objects to supplement natural landmarks indicating safe and unsafe waters.
ALEEAway from the direction of the wind. Opposite of windward.
ALL STANDINGTo have all sails flying when running before the wind.
ALOFTAbove the deck of the boat.
AMIDSHIPSIn or toward the center of the boat.
ANCHORAGEA place suitable for anchoring in relation to the wind, seas and bottom.
APPARENT WINDThe combination of the true wind and the wind caused by the boat’s own speed
ASTERNIn back of the boat, opposite of ahead.
ASTERN, TO GO ASTERNGo backwards, put the engine in reverse.
ATHWARTSHIPSAt right angles to the centerline of the boat; rowboat seats are generally athwart ships.
AUTOPILOTA device – may be electronic or mechanical – used for keeping the boat on course without having to steer it.. It uses a compass, and is attached to the boat’s steering mechanism.
AUXILIARY POWERAn engine that is permanently installed on the boat used for functions other than propulsion (although it occasionally is used to power the boat). Oars are sometimes referred to as the auxiliary power in jest.
AWEIGHThe position of anchor as it is raised clear of the bottom.
BAILERBucket for removing water from a boat to prevent it sinking.
BALLASTA very heavy material, such as lead or iron, placed in the keel of the boat, or in the bilge. It is used to provide stability.
BATTEN DOWNSecure hatches and loose objects both within the hull and on deck.
BEAMThe greatest width of the boat.
BEARINGThe 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.
BEARING AWAYTurning away from the wind.
BELOWBeneath the deck.
BILGEThe interior of the hull below the floor.
BILGE PUMPA pump to remove bilge water. Electric, manual pumps and buckets can be used for this function.
BIMINIWeather-resistant fabric stretched over a stainless steel frame, fastened above the cockpit of a sailboat or flybridge of a power yacht which serves as a rain or sun shade.
BITTER ENDThe last part of a rope or chain.The inboard end of the anchor rode.
BOATA very broad term for a waterborne vehicle smaller than a ship.
BOAT HOOKA short shaft with a fitting at one end shaped to facilitate use in putting a line over a piling, recovering an object dropped overboard, or in pushing or fending off.
BOOMA pole running at a right angle from the mast.
BOWThe front end of the vessel.
BOW LINEA docking line leading from the bow.
BOWERThe main anchor of a boat – carried at the bow.
BOWLINEA knot used to form a temporary loop in the end of a line.
BRIDGEThe location from which a vessel is steered and its speed controlled. “Control Station” is really a more appropriate term for small craft.
BRIDLEA line or wire secured at both ends in order to distribute a strain between two points.
BULKHEADA vertical partition separating compartments.
BUOYAn anchored float used for marking a position on the water or a hazard or a shoal and for mooring.
BURDENED VESSELThat vessel which, according to the applicable Navigation Rules, must give way to the privileged vessel. The term in many states has been superseded by the term “give-way”.
CABINA compartment for passengers or crew.
CAPSIZETo turn over.
CAST OFFTo let go.
CATAMARANA twin-hulled boat, with hulls side by side.
CENTREBOARDA pivoting board that prevents the boat from sliding sideways.
CHAFING GEARTubing or cloth wrapping used to protect a line from chafing on a rough surface.
CHARTA map for use by navigators.
CHINEThe intersection of the bottom and sides of a flat or v-bottomed boat.
CHOCKA fitting through which anchor or mooring lines are led. Usually U-shaped to reduce chafe.
CLEATA fitting to which lines are made fast. The classic cleat to which lines are belayed is approximately anvil-shaped.
CLOVE HITCHA knot for temporarily fastening a line to a spar or piling.
COAMINGA vertical piece around the edge of a cockpit, hatch, etc. to prevent water on deck from running below.
COCKPITAn opening in the deck from which the boat is handled.
COILTo lay a line down in circular turns.
COURSEThe direction in which a boat is steered.
CUDDYA small shelter cabin in a boat.
CUNNINGHAM (also called a Downhaul):Adjusting the tension of a sail’s luff.
CURRENTThe horizontal movement of water.
DAVITDevice (like a small crane) for lifting a tender on and off a boat.
DEAD AHEADDirectly ahead.
DEAD ASTERNDirectly aft.
DEADRISEThe design angle between the keel and horizontal. A vessel with a 0 degree deadrise has a flat bottom where as a a higher degree will indicate a deeper ‘v’ shaped hull.
DECKA permanent covering over a compartment, hull or any part thereof.
DECKHANDThe person responsible for cleaning the deck and generally maintaining the a vessel.
DINGHYA small open boat. A dinghy is often used as a tender for a larger craft.
DISPLACEMENTThe weight of water displaced by a floating vessel, thus, a boat’s weight.
DISPLACEMENT HULLA type of hull that plows through the water, displacing a weight of water equal to its own weight, even when more power is added.
DISTANCEWhere ‘miles’ are referred to as ‘nautical’ miles are meant One (1) nautical mile = 1.852 km
DOCKA protected water area in which vessels are moored.The term is often used to denote a pier or a wharf.
DRAFTThe depth of water a boat draws.
EBBA receding current.
ENSIGNA flag indictating the nationality of a vessel.
EPIRBEmergency Position Indicating Radio Beacon.
FATHOMSix feet.
FENDERA cushion, placed between boats, or between a boat and a pier, to prevent damage.
FIGURE EIGHT KNOTA knot in the form of a figure eight, placed in the end of a line to prevent the line from passing through a grommet or a block.
FLAREA distress signal. Also – the outward curve of a vessel’s sides near the bow.
FLOOD/FLOWA incoming current.
FLYBRIDGEA driving station above the main level of the boat.
FOLLOWING SEAAn overtaking sea that comes from astern.
FORE-AND-AFTIn a line parallel to the keel.
FOREPEAKA compartment in the bow of a small boat.
FORWARDToward the bow of the boat.
FOULEDAny piece of equipment that is jammed or entangled, or dirtied.
FREEBOARDThe minimum vertical distance from the surface of the water to the gunwale.
GALLEYThe kitchen area of a boat.
GANGWAYThe area of a ship’s side where people board and disembark.
GEARA general term for ropes, blocks, tackle and other equipment.
GIVE WAYSlow, stop, go astern or change course to keep clear of another vessel
GIVE-WAY VESSELA term used to describe the vessel which must yield in meeting, crossing, or overtaking situations.
GRAB RAILSHand-hold fittings mounted on cabin tops and sides for personal safety when moving around the boat.
GROUND TACKLEA collective term for the anchor and its associated gear.
GUNWALE/SThe upper edge of a boat’s sides (pronounced gunnels).
HARD CHINEAn abrupt intersection between the hull side and the hull bottom of a boat so constructed.
HATCHAn opening in a boat’s deck fitted with a watertight cover.
HEADA marine toilet. Also the upper corner of a triangular sail.
HEAD UPSailing closer to the wind.
HEADINGThe direction in which a vessel’s bow points at any given time.
HEADWAYThe forward motion of a boat. Opposite of sternway.
HEAVE TOSteering into the wind and sea making minimum headway
HELMThe wheel or tiller controlling the rudder.
HELMSPERSONThe person who steers the boat.
HITCHA knot used to secure a rope to another object or to another rope, or to form a loop or a noose in a rope.
HOLDA compartment below deck in a large vessel, used solely for carrying cargo.
HULLThe main body of a vessel.
INBOARDMore toward the center of a vessel; inside; a motor fitted inside a boat.
IRONSBoat is pointing into the wind, sail is flapping and probably also going backwards.
JACOBS LADDERA rope ladder, lowered from the deck, as when pilots or passengers come aboard.
JETTYA structure, usually masonry, projecting out from the shore; a jetty may protect a harbor entrance.
KEELThe centerline of a boat running fore and aft; the backbone of a vessel.
KICKER (also called a Vang)A device used to keep the boom from rising.
KNOTA measure of speed equal to one nautical mile (1.852km) per hour.
KNOTA fastening made by interweaving rope to form a stopper, to enclose or bind an object, to form a loop or a noose, to tie a small rope to an object, or to tie the ends of two small ropes together.
LATITUDEThe distance north or south of the equator measured and expressed in degrees.
LAYLINEThe course on which your boat, sailing close – hauled on starboard tack, can just make a windward mark which is to be rounded to port is the starboard – tack lay line for that mark, and the most windward line on which you would
approach the
mark on port tack is the port – tack lay line.
LAZARETTEA storage space in a boat’s stern area.
LEAGUEA unit of length, normally equal to 3 nautical miles
LEEThe side sheltered from the wind.
LEEWARDThe direction away from the wind. Opposite of windward.
LEEWAYThe sideways movement of the boat caused by either wind or current.
LENGTH OVERAL (LOA)The total length of a boat.
LENGTH WATER LINE (LWL)The length of the boat touching the water.
LIFE BUOYFloating safety ring to assist in “person overboard” situations.
LINERope and cordage used aboard a vessel.
LOGA record of courses or operation. Also, a device to measure speed.
LONGITUDEThe distance in degrees east or west of the meridian at Greenwich, England.
LUBBER’S LINEA mark or permanent line on a compass indicating the direction forward parallel to the keel when properly installed.
LUFFINGPointing the boat into the wind – sail flapping.
MAINSHEETLine that controls the position of the mainsail.
MAKING WAYVessel under way and moving through the water, using power or sail
MARKAn object the sailing instructions require a boat to pass on a specified side.
MARLIN BOARDLike a swim board. A small deck on the aft (rear) of the boat to make accessing the water easier.
MARLINSPIKEA tool for opening the strands of a rope while splicing.
MASTA pole usually going straight up from the deck (height can be tuned for different body weights), used to attach sail and boom.
MIDSHIPApproximately in the location equally distant from the bow and stern.
MOORINGAn arrangement for securing a boat to a mooring buoy or a pier.
NAUTICAL MILEOne minute of latitude; approximately 1.852kms
NAVIGATIONThe art and science of conducting a boat safely from one point to another.
NAVIGATION LIGHTSRed, green and white lights required by vessels between sunset and sunrise and in restricted visibility.
NAVIGATION RULESThe regulations governing the movement of vessels in relation to each other.
OBSTRUCTIONIs an object that a boat could not pass without changing course substantially to avoid it. e.g. a mark, a rescue boat, the shore, perceived underwater dangers or shallows.
OUTBOARDA detachable engine mounted on a boat’s stern.
OUTHAULAn adjuster that tensions the sail’s foot.
OVERBOARDOver the side or out of the boat.
PFDPersonal Flotation Device – Lifejacket. They come in categories 1, 2 & 3 depending on usage and are compulsory in Australia.
PIERA loading platform extending at an angle from the shore.
PILEA wood, metal or concrete pole driven into the bottom. Craft may be made fast to a pile; it may be used to support a pier.
PILOTINGNavigation by use of visible references, the depth of the water, etc.
PITCHA vessel’s motion, rotating about the beam axis, so the bow pitches up and down.
PLANINGA boat is said to be planing when it is essentially moving over the top of the water rather than through the water.
PLANING HULLA type of hull shaped to glide easily across the water at high speed.
PLIMSOL LINEThe mark on the hull of a ship that shows where the waterline is when the boat is at full capacity.
PORTThe left side of a boat looking forward. A harbour.
PORT TACKWind across the port side.
PRIVELEGED VESSELA vessel which, according to the applicable Navigation Rule, has right-of-way.
PWCAny recreational vessel that is of a kind that is required to be registered and that: is power driven, has a fully enclosed hull, does not retain water on it if it capsizes or is designed to be operated by a person standing,
sitting astride
or kneeling on the vessel, but not seated within the vessel.
QUARTERThe sides of a boat aft (behind) of amidships (middle of ship).
REACHINGSailing with the sail eased.
REEFINGReducing the amount of sail area.
RIGThe arrangement of a boat’s mast, sails and spars.
ROPEIn general, cordage as it is purchased at the store. When it comes aboard a vessel and is put to use it becomes line.
ROLLA vessel’s motion rotating from side to side, about the fore-aft axis. “List” is a lasting tilt in the roll direction
RUDDERAn underwater vertical plate or board for steering a boat.
RUNTo allow a line to feed freely.
RUNNING LIGHTSLights required to be shown on boats underway between sunset and sunrise.
RUNNINGSailing before the wind with the sail out.
SAIL TRIMThe position of the sails relative to the wind and desired point of sail.
SAND BARAn area in shallow water where wave or current action has created a small, long hill of sand. Since they are created by water movement, they can move and may not be shown on a chart.
SATELLITE NAVIGATION (SAT. NAV.)A form of position finding using radio transmissions from satellites with sophisticated on-board automatic equipment.
SCOPEThe ratio of length of anchor line in use to the vertical distance from the bow of the vessel to the bottom of the water.
SCREWA boat’s propeller.
SCUPPERSDrain holes on deck, in the toe rail, or in bulwarks or (with drain pipes) in the deck itself.
SEA COCKA through hull valve, a shut off on a plumbing or drain pipe between the vessel’s interior and the sea.
SEA ROOMA safe distance from the shore or other hazards.
SEAMANSHIPAll the arts and skills of boat handling, ranging from maintenence and repairs to piloting, sail handling and rigging.
SEAWORTHYA boat or a boat’s gear able to meet the usual sea conditions.
SECURETo make fast.
SETDirection toward which the current is flowing.
SEXTANTA navigational instrument used to determine the vertical position of an object such as the sun, moon or stars. Used with celestial navigation.
SHIPA larger vessel usually thought of as being used for ocean travel. A vessel able to carry a “boat” on board.
SLACKNot fastened; loose. Also, to loosen.
SOUNDINGA measurement of the depth of water.
SPEEDAll speeds are measured in ‘knots’ One knot = 1 nautical mile per hour
SPINNAKER POLESometimes called a spinnaker boom. A pole used to extend the foot of the spinnaker beyond the edge of the boat, and to secure the corner of the sail.
SPINNAKERA very large lightweight sail used when running or on a broad reach.
SPREADERSmall spars extending toward the sides from one or more places along the mast. The shrouds cross the end of the spreaders, enabling the shrouds to better support the mast.
SPRING LINEA pivot line used in docking, undocking, or to prevent the boat from moving forward or astern while made fast to a dock.
SQUALLA sudden, violent wind often accompanied by rain.
SQUARE KNOTA knot used to join two lines of similar size. Also called a reef knot.
STARBOARDThe right side of a boat when looking forward.
STARBOARD TACKWind across the starboard (right) side.
STEMThe forward most part of the bow.
STERNThe back end or rear of a vessel
STERN LINEA docking line leading from the stern.
STOWTo put an item in its proper place.
STRONG WIND WARNINGA warning for small craft when winds of 25 knots are expected.
SWAMPTo fill with water, but not settle to the bottom.
SWIMBOARDA platform at the back of the boat to allow easy access to the water.
TACKINGChanging direction by turning into the wind.
TENDERA small boat used for moving passengers from shore to the main boat or ‘mother boat’.
TIDEThe periodic rise and fall of water level in the oceans.
TILLERA bar or handle for turning a boat’s rudder or an outboard motor.
TOPSIDESThe sides of a vessel between the waterline and the deck; sometimes referring to onto or above the deck.
TRANSOMThe stern cross-section of a square sterned boat.
TRIMFore and aft balance of a boat.
TRUE WINDThe strength and direction of the actual wind blowing. While sailing, the true wind is never felt – it is always a combination of the true wind, and the boat’s speed (called the apparent wind), and it is always a little forward
to the true
UNDERWAYVessel in motion, i.e., when not moored, at anchor, or aground.
V BERTHBunks forming a V at the front of a boat
V BOTTOMA hull with the bottom section in the shape of a “V”.
V SHEETA fluorescent orange-red coloured sheet (1.8×1.2m) with a large black “V” printed in the middle. V-Sheets are required to be carried by all vessels operating off shore. They can be spread over the deck of a boat or flown as a
flag to indicate
that you are in trouble.
WAKEMoving waves, track or path that a boat leaves behind it, when moving across the waters.
WASHSame as Wake – Waves made by a vessel making way
WATERLINEA line painted on a hull which shows the point to which a boat sinks when it is properly trimmed
WAYMovement of a vessel through the water such as headway, sternway or leeway.
WINDWARDToward the direction from which the wind is coming (upwind).
YACHTA pleasure vessel, a pleasure boat. Can refer to sail or power vessel.
ZINC BLOCKA sacrificial block of metal, usually zinc, to be eaten away by electrolysis under water, saving your underwater metal parts