Bear’s Dictionary of Modern Powerboat Terms
I have specifically named this "Bear's Dictionary of Modern Powerboat Terms" as I have tried to modernise, and give personal understanding and experience to many of the descriptions. There's also a bit of "old sea dog humour" to be found in places.
If I were to include sailing and more historic nautical terms in this dictionary it would become a bible rather than a quick reference. This is not about sailing vessels - Sailors can do their own! This dictionary references boating terms for recreational vessels with some general items thrown it.
I hope you find it useful.
A
Abandon Ship - A command to exit the vessel quickly, typically due to danger. A command we hope we will never hear!
Abeam - Alongside or at right angles to the centerline of a boat.
Aboard - On or inside the boat.
Adrift - Floating freely without being anchored or powered.
Afloat - A vessel that is floating freely, not grounded or sunk.
Aft - Towards the rear or stern of the boat.
Aground - A vessel touching or stuck to the bottom, usually unintentionally.
Ahead - Moving or positioned in a forward direction from the boat.
Ahoy - A call to get attention.
AIS - Automatic Identification System.
All-Round Light - A light that displays continuously in a 360-degree arc
Alongside - Next to a ship or pier.
Amidships - The center of the deck of the vessel between the fore-and-aft.
Amidships - The central portion of the boat.
Anchor - The weight or device dropped to the bottom of the waterway with rope (rode) and chain to maintain the position of the boat.
Anchor Ball - A round black sign raised at the front of a vessel to indicate it’s anchored – or an anchor lifting device.
Anchor Buoy - A small buoy attached to an anchor with a light line to show its position on the seabed.
Anchor Well – A recess or locker to store the anchor, rope (rode) and chain.
Anchor Winch – A manual or mechanical device to raise and lower the anchor.
Anchorage - A location for safe anchoring. It can also refer to a harbour.
Anode – Marine anodes are typically made of zinc. They are a sacrificial first line of defence in an engine or drive as they give off electrons and corrode before the other metals can be affected.
As the Crow Flies - The shortest distance between two points.
Ashore - On the land or beach.
Astern - Behind or towards the rear of the boat.
At Loggerheads - In disagreement or conflict.
Attitude - The riding characteristics of a boat underway
Auxiliary Power - A backup engine/generator or battery bank on a boat.
B
Bailer - A tool for removing unwanted water from a boat. Usually a bucket. (Boaters often use it for peeing! LOL)
Ballast - Weight added to the lower portion of the hull to improve stability or attitude.
Bar - A shallow area of sand or earth in the sea, often near river mouths, that can be hazardous to navigation.
Bass Boat - A type of boat that generally has a flat deck, low freeboard, and a shallow draft that is used primarily for fishing protected lakes and rivers.
Batten Down - Secure loose objects and hatches on the boat.
Beam - The beam of a ship is its width at its widest point.
Bearing - The direction of the craft measured in magnetic or true degrees.
Below - Under the boat’s deck.
Berth - A sleeping quarters on a boat, or a mooring occupied by a vessel in a marina or harbor.
Bilge - The lower part of the hull where water collects.
Bilge Pump – a manual or mechanical pump for removing water from the bilge
Bimini - A weather-resistant fabric stretched over a frame, providing shade above a boat’s cockpit.
Bitter End - The end of a line, or more commonly the fitting that’s attached to a vessel.
Boat - A waterborne vessel smaller than a ship. (An old colleague of mine once comically declared that a boat becomes a ship when crew members wear epaulettes!)
Bombora - A wave that forms over an underwater rock or submerged reef, sometimes producing a dangerous water area.
Bow - The front, most often the pointy end of a boat.
Bow Cockpit - A forward deck or seating area of a boat. (most often called the bowrider)
Bow Line - Dock lines secured to the bow of a boat.
Bow Sprit - A bow extension that retains the anchor
Bowrider - A forward seating/entertainment area of a boat
Bow Rider - A powerboat with a seating area set in its bow.
Bridge - The place where a vessel is driven.
Bridle - A line or wire secured at both ends to distribute strain. Or, a line attached to the anchor rode and the rear bollard that adjusts the angle of the boat at anchor.
Broach - The heeling action of the boat when it slews to the broadside while running downwind. Abroach usually occurs in heavy seas with the stern attempting to overtake the bow.
Bulkhead - A partitioning wall in a vessel.
Buoy - A floating marker usually anchored in place for navigation or mooring.
C
Cabin – the internal part of a boat
Cabin Cruiser - Generally, any larger powerboat that provides sleeping accommodations within its structure. This generic term can be used to describe motor yachts, expresses, and a number of different designs.
Canopy and clears - A combination of canvas shade and usually removable clear front and side windows surrounding the helm.
Capsize - When a boat overturns.
Casting Platform - A raised area in a boat mainly used for lure fishing
Catamaran - A craft with two hulls.
Center-Line - The center of the vessel along the aft-to-fore line.
Centre Console - a helm console in the middle of an open boat.
Centre-Board - A board lowers through a slot on the keel for reducing leeway.
Chart - A marine map used by navigators.
Chine - The point where the bottom and sides of a flat or v-bottomed boat meet.
CHIRP Sonar - CHIRP sonar uses a combination of different frequencies to gather more complete and more detailed information for the processor.
Cleat - A fitting used to secure ropes.
Coaming - The upper sides of the boat deck.
Coaming racks - Side-mounted fishing rod/boat hook/gaff storage
Cockpit - The living, working, and entertaining area of a boat.
COLREGS - International Regulations for Preventing Collisions at Sea
Companionway - An entryway that provides access below-decks.
Compass - Instrument showing the boat’s direction relative to Earth’s poles.
Course - The direction that you steer the vessel in measured in degrees.
Cuddy - A small, sheltered cabin on a boat.
Current - The horizontal movement of water.
D
Davit – A crane-like device used on a vessel for supporting, raising, and lowering equipment
Dead Ahead - Directly in front.
Dead Astern - Directly behind the vessel.
Dead Reckoning - A method of navigation.
Deadrise - The angle of a hull’s “V” shape, usually measured in degrees at the transom.
Deck - a floor, walkway or covering over a compartment or vessel hull.
Deck Boat - A powerboat with a flat, open deck plan with a similar layout to a bowrider. Most deck boats have a rather boxy shape, instead of tapering to a point at the bow, to create more forward deck space.
Deviation - The difference between the direction indicated by the magnetic meridian and the compass needle, usually caused by metal objects interfering with the compass operation.
Dinette - A usually convertible seating dining area
Displacement - A vessel's weight.
Displacement Hull - A hull design that moves through the water by displacing its own weight and is only supported by its buoyancy.
Dock - A flat walkway usually secured to pilings that boats tie up to. Docks can either be fixed or floating.
Draft or Draught - The depth of a ship’s keel below the waterline.
Drift - To float the vessel with the wind or current. Or the distance the boat covers while drifting in the current, measured in time.
Drogue - A sea anchor causing drag to reduce drift or slow the hull.
Dry Weight - The weight of a boat without fuel or water onboard.
Dual Console - A boat with twin dashboards that are separated by a walk-through that allows access to a forward cockpit or seating area.
E
Ebb - A receding current, typically when the tide falls and the water level lowers.
Echo Sounding - A method to measure water depth using sonar.
Enclosed Waters - navigable waters enclosed by land or a port.
EPIRB - Emergency Position Indication Radio Beacon.
ETA - Estimated Time of Arrival.
ETD - Estimated Time of Departure.
Express Boat - A powerboat with a steering station on deck level, no flying bridge, and a cabin forward of, usually lower than the helm station.
F
Fairlead - A fitting designed to guide a rope or chain, keeping it clear of obstructions and preventing it from cutting or chafing.
Fairway Buoy - A marker used to indicate the start and end of a buoyed section of a channel. A series of them may mark a safe route through shallow areas
Fairway - A navigable channel or waterway.
Fathom - Measurement of water depth and rope lengths. 1 Fathom = 6-feet = 1.83-meters.
Fender - An inflatable cushion used to protect a boat from contact.
Finger Pier - A slender walkway that branches out from a dock and divides two slips.
Fiddle - The raised border on marine furniture, preventing objects from falling off the surface.
Fix - The vessel position as plotted by two or more positioning lines.
Flare - A signalling device indicating distress or the outward curve of a vessel’s sides near the bow.
Flats Boat - A powered skiff designed with an extremely shallow draft for fishing on flats and other shallow water areas.
Flood Tide - A tide that is increasing or coming in.
Fluke - The palm or flat part of an anchor.
Flybridge - A raised deck on a vessel usually having its own, or a duplicate helm.
Following Sea - Waves moving in the same direction as the vessel.
Fore and Aft - In a line parallel to the keel.
Forward - Toward the bow of the boat.
Fouled - Equipment that is jammed, entangled, or dirtied.
Freeboard - The vertical distance between the top of the deck and the waterline.
G
Galley - The kitchen in a vessel or aircraft
Gangplank - A movable bridge for boarding or leaving a ship at a pier.
Gangway - An opening in the vessel's side for boarding or disembarking.
Gear - A general term for ropes, blocks, tackle, and other equipment.
Gimbal - A device for keeping an instrument such as a compass or chronometer horizontal in a moving vessel or aircraft, typically consisting of rings pivoted at right angles. Also a fishing rod support worn around the waist.
GPS - Global Positioning System.
Ground Tackle - A term for the anchor and its associated gear.
Guard Rail - This rail surrounds the boat’s edges, allowing easy gripping to prevent falling overboard.
Gunwale/gunnel - The gunwale is the top edge of the hull. A rubbing strip is often called the gunwale rail.
H
Hard Top - A solid cover to the helm or flybridge
Hatch - An opening over a door or compartment.
Hawse Pipe/Hole - The hole in a ship’s bow/deck for the anchor chain.
Head - Marine toilet.
Head Sea - Waves coming directly against the ship’s direction.
Heading - The direction of the vessel in degrees.
Headway - The forward motion of the vessel through the water.
Heave - The up-and-down motion of a vessel.
Heel - When the vessel exaggeratedly leans to one side.
Helm - The control centre for a vessel speed and direction.
Hitch - A type of knot.
Hold - An enclosed space or compartment within a vessel's hull where cargo is stored.
House Boat - Boats that have large home-like accommodations built on a barge-like hull.
I
Inboard - The main drive of the vessel is located within the hull.
Inflatable Boat: Any boat with inflatable hull/sponsons.
Isobars - The lines on weather maps join places with equal atmospheric pressure.
J
Jet drive - a water pump that generates a high-speed jet of water which is ejected through a nozzle that has directional control for steering.
Jury - The temporary device for replacing damaged or lost gear.
K
Kedge - A secondary, smaller, mostly lightweight anchor.
Keel - The bottom center line of the vessel.
Keel Over - Refers to a boat capsizing; also means passing out or dying. (Often after too much rum, LOL)
Knot (speed) - A unit of speed equal to one nautical mile per hour.
L
Lanyard - A short length of line attached to an object for safety.
Latitude - The distance north or south of the equator, measured in degrees.
Leads - Marks indicating the centre of a navigable channel when aligned.
Leeward - Moving in a direction away from the wind. The direction in which the wind is blowing.
Leeway - The sideways motion off course resulting from the wind blowing on one side of the vessel.
Life Buoy - Floating ring used for safety in water.
Lifeboat - Small vessel for safety, often used in emergencies.
List - The vessel leans to one side due to windage or improper weight distribution.
Live Sonar - Modern underwater sonar system that shows live/moving data similar to an ultrasound. Various electronics producers have registered names such as Panoptics, Active Target etc.
Locker - A storage compartment on a vessel.
Log - Record of operations or a device to measure speed.
Longitude - Distance in degrees east or west of Greenwich, England.
M
Making Way - Vessel moving through water under power or sail.
Man Overboard - Alert given when someone falls into the water.
Marina - Place for boats to get mooring, shelter, fuel, water, and services.
Marinised Engine - An engine adapted for use in watercraft.
Mark - A reference point for navigation, recording or race requirements.
Marlin Board - Small deck at the rear for easy water access.
Masthead - the highest part of a ship's mast. In powerboats we generally find this a mounting point for the masthead light (visible 360 degree)
Mayday - An international distress signal used in the most urgent life-threatening situations
Meridian - A longitudinal line circling the earth, passing through both poles, cutting at right-angles through the equator.
Moor - To secure a boat to an anchorage, buoy, post, or dock.
Mooring - System to secure a boat to a buoy or pier, or a safe/secure on-water resting position.
N
Nautical Miles - Distance equal to 1.852 km or 1.151 miles; used in maritime navigation.
Nautical - Any marine-related item or activity.
Navigation Lights - Lights on a vessel for nighttime or low visibility.
Navigation - Art of guiding a boat safely from one place to another.
NMEA 2000 - abbreviated to NMEA2k or N2K and standardized as IEC 61162-3, is a plug-and-play communications standard used for connecting marine sensors and display units.
O
Open Waters - Navigable waters not enclosed, mostly referred to as the ocean.
Outboard Motor - a marine propulsion system consisting of a self-contained unit that includes engine, gearbox and propeller or jet drive, designed to be affixed to the outside of the transom.
Outboard Well - A drained recess inside the transom where the outboard motor/s are attached.
Outrigger - A secondary buoyancy device attached to the hull, or a set of long poles that tilt down to extend the trolling width.
Overall Length (LOA) - The extreme length of the vessel. The measurement from the aftmost point of the stern to the foremost points of the bow.
P
Painter – a relatively short bowline usually used for launch/retrieve.
Pan Pan - An international signal used to declare a state of urgency/warning, but for the time being, it does not pose an immediate danger to anyone's life, or to the vessel itself.
Pay Out - To gradually let out the rope.
Personal Flotation Device (PFD) - Lifejacket, categorized by usage.
Personal Watercraft (PWC) - Small vessel such as a jet ski
Pier - Loading platform extending from the shore.
Pile - A pole driven into the bottom, used for support or to tie boats.
Piling - Supports made of piles, used for wharves, piers, etc.
Pilot - Expert navigator for guiding vessels through challenging waters.
Pitch - Boat’s up and down motion at the front and back.
Planing Hull - A boat designed to glide on water at high speeds.
Planing - When a boat skims on the water’s surface due to high speed.
Plimsol Line - Mark showing the waterline when a ship is fully loaded.
Pod Drives - Inboard engines mounted above articulating drive units that protrude through the bottom of the boat.
Pontoon Boat - A flat-decked boat with a perimeter fence built atop two or more pontoons.
Port Side - Left side of a boat when facing forward; also a harbour.
Porthole - window on a ship’s side.
Propeller - A rotating device that is paired with an engine to propel a boat through the water.
Pulpit - A guard rail fitted to the bow to provide additional safety for the crew.
Pushpit - A guard rail fitted around the stern of the boat to provide additional safety for the crew.
Q
Quarter - The section of the vessel midway between the beam and the stern.
Quartering Sea - Sea waves approaching a boat’s side towards the stern.
R
Radar Reflector - Device enhancing a vessel’s visibility on radar.
Radar - Electronic system to detect objects by reflecting radio signals.
Range - The difference in water levels between the high and low tides. Or the distance you can travel with onboard fuel. Or a visible distance.
Reef - Rocky structure either below or adjacent to the water, or to shorten a sail.
Rhumb Line - The proposed course of the vessel.
Rigging - Lines, controls, instruments, accessories and wires
Rigid Inflatable Boat (RIB) - An inflatable boat with sponsons built around a rigid hull.
Rocket Launcher – Overhead fishing rod storage
Rode - The line and/or chain connected to an anchor.
Roll - Boat’s side-to-side rocking motion.
Rope - Cordage as bought from a store; becomes “line” when used on a vessel.
Rubrail - A protective outer element on the hull sides that helps protect the hull from damage. Also called gunwale rubber/protection.
Rudder - A vertical appendage that controls steering.
Run - The act of steering with the wind to the aft of the vessel.
Runabout - A generic term used for any small powerboat, generally meant for day-boating with limited (if any) below-decks accommodations.
Running Lights - Lights on boats used from sunset to sunrise while moving.
S
Sailboat - Any boat driven by sails.
Saloon - The primary internal living/entertaining area or an enclosed hardtop style boat.
Sandbar - Raised sandy area in shallow water.
Screw - Another term for a boat’s propeller.
Scuppers - Drains on a boat’s deck or sides.
Sea Anchor - A drogue causing drag to reduce drift or slow the hull.
Sea Room - The room in which the vessel can manoeuvre clear of dangers.
Seacock - A shut-off valve for the underwater outlet or inlet passing through the vessel’s hull.
Seals – Seawater or lubricant retainers for shafts, bearings, sea cocks etc
Seamanship - Skills and knowledge related to boat handling and maintenance.
Seaworthy - A boat’s ability to safely navigate at sea.
Secure - To fasten or make tight.
Sécurité - (often repeated thrice, "Sécurité, sécurité, sécurité") is a procedure word used in the maritime radio service announcing a warning of important safety information.
Set - The direction a current is flowing towards or a vessel's angle in the water.
Shackle - A steel link featuring a removable bolt crossing the open end. The shackle comes in various designs, from “S” to “U” shapes.
Shaft Drive – An inboard engine with a driven shaft powering the drive or propeller.
Sheer Line - The outline of a boat’s deck at the gunwale or hull-deck joint from bow to stern.
Ship - A large vessel (Some of the crew wear epaulets!!!LOL)
Side Console - a helm console on the side of an open boat
Side door – Door in the side of the cockpit
Side pockets – Pockets in the sides of the boat inside and out.
Skin Fitting - A through-hull fitting featuring a hole in its skin that allows for air and water passing.
Skipper - The person responsible for operating and ensuring the safety of a boat or ship; the captain. (Sometimes wears epaulettes! LOL)
SOG - Speed Over the Ground
SOLAS - Safety of Life at Sea. SOLAS, 1974 is an international treaty that sets minimum standards for the construction, equipment and operation of merchant ships. Also a brand of propeller.
Sounding - The action or process of measuring water depth and searching the water column.
Spar Lash - The sound the anchor makes when it hits the water – SPALASH! LOL
Splice - Joining or the joint where wires or ropes are connected using a weaving process interlacing the fibres.
Sponson - A projection from a ship’s side, serving various purposes like protection or as a gun platform. Also the individual hulls of a multi-hull vessel.
Spring Line (Springer) - Dock lines used to prevent a boat from moving forward and aft.
Squall - A sudden, strong burst of wind, often accompanied by rain.
Stanchion - The post bolted to the deck in an upright position to support the guard railing.
Standing Part - The part of the line you don’t use when making a knot. Or the part of a rope you use to tie around the knot.
Starboard - The right-hand side of the vessel when looking forward.
Stateroom - An enclosed cabin in a boat with sleeping quarters
Stay - The rope or wire supports a mast or similar such as outriggers in the fore-and-aft direction.
Steerage Way - The vessel has steerage when it reaches sufficient speed, allowing for steering or answering the helm.
Stem - The frontmost part of a boat’s bow.
Stern - The rear end of the vessel
Stern Line: Dock line secured to the stern of a boat that limits its movement.
Stern Drive - An outboard drive unit at the rear of a powerboat connected to an inboard engine.
Stow - To store or place an item in its designated spot.
Strong Wind Warning - A warning is issued when winds exceeding 25 knots are expected.
Surge - A boat’s forward and backward motion.
Swamp - To fill a boat with water without sinking to the bottom.
Sway - A boat’s side-to-side motion.
Swell - Swell is a linear, long range wave pattern created by weather, geological, astrological or topographical event.
Swim Platform/Transom Platform/Marlin Board/Swim Board - A platform at the back of a boat for easy water access.
Switch Baiting – A method of fishing where fish are teased up to a boat and then a rigged bait, usually live, is cast back to hook them.
T
Tack - the action of turning the boat through the wind to get it to blow on the other side of the hull/sails.
Tell-Tale - An outlet from the cooling system on an outboard engine indicating its operation.
Tender - A description for any small boat, often inflatable models used for access/servicing a larger craft.
Terminals - The metal fitting forming eyes or similar connections at the end of cables, wires, or ropes.
Tide - The regular rise and fall of the sea’s water level due to gravitational interactions with the Moon and Sun.
Tiller - A handle used to steer a boat’s rudder or an outboard motor.
Toe Rail - The low rail running along the edge of the deck to lock your toes/feet under increasing stability.
Topsides - The sides of the hull between the waterline and the deck.
Tow Boat - A boat designed and built for watersports such as wakeboarding, wake surfing, or water skiing. Often, these are also called watersports/wake/surf/ski boats.
Track - The course of the boat making good on its travel plan. Or a course for a slide fitting or canopy.
Trampoline - The netting stretching across the hulls of a catamaran.
Transducer (Marine) - a device that converts variations in a physical quantity, such as pressure or brightness, into an electrical signal, or vice versa in marine sonar.
Transom - The rear/aft section of a hull.
Travel lift - A mobile crane with lifting straps for boats
Trawler Style - A recreational powerboat with an upright cabin and windscreen that resembles commercial fishing trawlers.
Trim - To adjust the load, engine angle, boat direction and trim tabs/stabilisers to achieve optimum hull efficiency. Also the fittings and finishes in a boat.
Trim Tabs - Plates/fittings on a powerboat’s hull bottom or transom that help adjust the boat’s running attitude, pitch, and roll as it moves through the water.
Trimaran - Any boat with three hulls.
Trolling - A method of fishing in which a lure or a bait is pulled behind a boat at varying speeds and depths according to the nature, habitat, and size of the fish being sought. (As opposed to those annoying idiots on the internet!)
T-Top – An overhead structure on a boat, most often a centre console that is usually topped with a section of canvas or a hard top to protect occupants from sun, spray, and rain as well as a mounting point for aerials, rod holders and accessories.
Turn Buckle – An adjustable, double-ended connection point for the tensioning load.
U
Under the Weather - Feeling ill (Often caused by too much rum the night before! LOL)
Underway - When a boat is moving and not anchored or moored.
Upwind - The direction from which the wind is coming.
V
Vanishing Angle - The maximum tilt degree after which a boat can’t return to an upright position.
V-Berth - Sleeping areas in the shape of a “V” at the front of a boat.
V-Bottom - A boat hull shaped like a “V”.
Veer - The wind will veer when shifting in a clockwise direction. Or a change of track/COG.
Vessel - A broad term for all waterborne vehicles.
VHF (Very High Frequency) - Radiofrequency used for marine communication.
V-Sheet - A red sheet with a black “V” used to signal distress.
W
Walkaround - A boat built with side decks to walk around the cabin and up to a foredeck.
Wake - The disturbed water/waves left behind (astern) the boat as it moves forward in the water.
Wash - Waves created by a moving vessel. Or to clean.
Waterline Length - The length of the hull where it intersects the water, from bow to stern.
Waterline - The line on a boat’s hull where it meets the water
Wavelength - The distance between the radio waves. Or the distance between identical points in the adjacent cycles of crests of a wave. It is usually measured in metres.
Wave Amplitude - the maximum distance (positive or negative) a wave reaches from its rest position. It is usually measured in metres and is directly related to the amount of energy carried by a wave.
Wave Period - the time taken for a full wave cycle, usually measured from peak to peak, or trough to trough.
Wave Frequency - the number of waves passing a point each second. A wave with a larger frequency has more energy.
Way - A boat’s movement through the water.
Waypoint - A navigational point defined by coordinates.
WGS84 - World Geodetic Survey of 1984 (most common chart datum).
Winch - A geared manual or mechanical device featuring a cable or line for pulling and lifting.
Windage - The parts of the vessel exposed to the forces of the wind.
Windlass - A winch used in hauling up the anchor chain/rode.
Windward - The direction from which the wind blows (the opposite way to leeward).
X
XTE - Cross Track Error. The perpendicular distance between two waypoints off-track.
Y
Yacht - A luxury boat, either sail or power-driven.
Yaw - A boat’s side-to-side movement, especially when off course or at anchor.
Z
Zephyr - A gentle breeze.
Zinc Block — A sacrificial metal block, typically zinc, used to prevent corrosion of a boat’s underwater parts due to electrolysis.
Buying a Boat Soon?
Check out our selection of boats for sale here at Only Boats! You'll find great opportunities to buy used boats and new boats, including ski boats, fishing boats, wakeboarding boats, and more!
For a great deal on financing your new purchase, contact Australia's best reviewed finance broker on 1300 Credit (1300 273 348) today or visit CreditOne.com.au