A

Anchorage

An area in which it is suitable to anchor a boat.

Anchor light

An all-round white light that by law is required to be visible when the boat is anchored or moored at night.

Anchor rode

The rope and/or chain and/or other line that connects the anchor to the boat.

Antifouling

A paint applied to boat hulls (usually those stored on the water) to resist unwanted growth such as marine algae/weed and barnacles.

B

Bar

A raised seafloor formation, usually sand or mud, that forms across the entrance to a river/harbour/bay.

Beam

A common term used for the width of a boat hull. (It can also refer to the direction that is perpendicular to the hull’s path.)

Berth

A place where a boat is secured fast, such as in a marina. (It can also refer to an onboard sleeping area.)

Bilge

The lowest area of the inside of a boat’s hull.

Boathook

A pole with a hooked end used for retrieving rope.

Bollard

A fitting used on boats, jetties, piers, marinas, etc., for fastening mooring lines (ropes).

Bow

The front part of a boat.

Bowsprit

A fitting designed to aid in anchoring duties; it protrudes from the bow and aside from its functional purpose also prevents anchor rode from damaging the hull surface.

Broaching

When a boat makes a sudden an uncontrolled turn that leaves the hull broadside (side-on) to the swell.

Buoy

A floating navigation marker used to indicate a location or navigation instruction; for example, marking a hazard, an exclusion zone, or suggested path of travel.

C

Chandlery

A collective term used for nautical equipment, including everything from cleats, shackles and ropes, to anchors, maps, sails and all in between.

Channel

An area that is deep enough to provide a safe navigable path of travel.

Chart

A map for the sea that displays useful information such as geography, depths, navigation aids and legal/safety notes.

Chine

The area of the hull where the bottom and topsides meet.

Cleat

A boat fitting used to attach mooring lines (ropes).

Course

The direction in which a boat is required to be steered.

D

Deadrise

The angle from the bottom of a boat hull to its widest beam; often used to describe the shape of a v-hull, thereby indicating certain performance attributes.

Displacement

The volume of water displaced by a boat when it is floating.

Draft

The vertical height from the lowest part of the hull bottom to the waterline; indicating the minimum water depth required for the boat to be floating.

E

F

Fathom

A nautical depth measurement equal to six feet (6’0”), or 1.82m.

Fender

A soft protective device positioned between a boat and an object to which it is fastened.

Fly bridge

Or 'flying bridge': a high steering position (often found on gameboats).

Following sea

When the waves are coming from astern (behind the boat).

Freeboard

The vertical height between the waterline and the top of the gunwales.

G

Ground swells

Sea swells that rise to become steeper and shorter as you move closer to shore.

Ground tackle

The anchor, anchor rode and other items attached to the anchor.

Gunwale

Often incorrectly spelled ‘gunnel’: the top edge of a boat’s sides.

H

Head

The boat's onboard toilet.

Heel, heeling

When a boat leans to one side.

I

J

K

Keel

The main central length-way structure of a boat.

Knot

A nautical speed measurement equal to one nautical mile per hour (1.85km/hour).

L

Lee shore

The shore towards which the wind is blowing. The term ‘in the lee’ refers to when you are sheltered from the wind.

Length on the waterline (LWL)

This term is often used in boat brochures and refers to the length of a boat’s line of floatation; where the water surface sits against the hull.

Length overall (LOA)

This term is often used in boat brochures and refers to a boat’s total length, from the tip of the bow to the very end of the stern, including any protruding motor or other parts.

M

Magnetic north

The direction in which a compass needle points. This is different to ‘true north’ (see below).

Mooring

A place where boats are fixed at anchor, often marked with buoys that are attached to the bottom with rope/chain and ground weights.

N

Nautical mile

An international standard unit of measurement equal to 1.852km. (Not be confused with a standard mile, which measures 1.609km.)

Neap tide

This occurs on the quarter moon and three-quarter moon and results in the least amount of range between the high and low tide.

O

Oarlock

A device used to hold oars in place for rowing.

Offshore

When referring to a direction: from land towards water. When referring to a location: usually when you’re far enough out to sea that you cannot see land.

Outboard motor

An engine attached to the transom of a boat.

P

PFD

Personal Floatation Device: The official name for a life jacket, or life preserver.

Pitch

The rise and fall of a boat’s bow as it moves through waves. This term is also used to differentiate propellers, basically acting as a sizing measure, describing the supposed forward distance movement of a propeller in one revolution.

Port

The left side of a boat (when facing the bow).

Q

Quarter

Used to name an area of a boat: the rear side quarter, from the boat’s centre to stern. You might say either ‘the portside quarter’ or the 'starboard quarter'.

Quartering sea

When waves are coming towards the boat’s quarter.

R

Ribs

A name used for the cross-way parts of a boat’s internal frame.

Roll

The continuing movement of a boat from port to starboard and back.

Running lights

Also called navigation lights: lights required by law for use at night or in low-light conditions. Examples of common trailer boat running light requirements that must be used between sunrise and sunset include a red portside light in conjunction with a green starboard light for when underway; and an all-round white light for when at anchor.

S

Screw

Another name used for propeller.

Scuppers

Drainage holes that allow water to run off the deck and outside the hull, back into the sea.

Sea anchor

A parachute- or cone-shaped device that has an open tip section. It is usually made of nylon or canvas and is never deployed to attach to the seafloor; it holds mid-water and is used to either slow a boat’s drift, or to keep the bow facing to the seas in open water.

Sea cock

A valve for a through-hull fitting used to open or close water flow to an inboard device such as a live bait tank or deck wash.

Squall

A sudden storm.

Starboard

The right side of a boat (when facing the bow).

Stern

The rear end of a boat.

Stern drive

A type of inboard motor configuration that combines with a below-water outboard propeller unit.

Swell

Long, often unrelenting, waves that appear uniform and that are separated by time periods, usually moving in from some distance away.

T

Tender

A small boat used to service a larger boat, transporting people/supplies/equipment to and from shore.

Thwart

A boat seat fixed crossways that is usually found in small open boats.

Tiller

An arm attached to a motor or rudder used to control the steering of a boat.

Tiller-steer motor

An outboard motor fitted with a tiller to control steering, and often acceleration, with a built-in hand throttle.

Topsides

A boat’s sides above its waterline.

Transom

The rearmost crosspiece of a boat’s stern.

True north

Geographic north (as indicated on maps).

U

Underway

This is a reference to a moving boat but can also indicate a boat that is simply not anchored, not aground, nor fastened to anything.

Upwind

In the direction from which the wind is blowing.

V

W

Wake

The track made in the water as a boat moves along.

Wash

Displaced water, usually a mix of waves and broken water moving outwards from the boat’s stern as the boat moves along.

Wide berth

Allowing for a lot of space between the boat and passing boats/objects.

Windlass

A winch used for retrieving anchor rode.

Windward

The direction from which the wind is coming from.

Y

X

Z