Glossary of Sailing Terms

A comprehensive collection of sailing vocabulary terms and definitions covering boat parts, points of sail, navigation aids, and nautical maneuvers.

Abeam

Off the side of (at right angle to) the boat.

Aft

At or toward the stern or behind the boat.

Aids to Navigation (ATON)

Buoys and beacons that indicate channels or show the location of submerged hazards.

Amidships

Toward the center of the boat.

Apparent wind

The speed and direction of the wind felt aboard a moving boat.

Athwartships

Across the boat from side to side.

Backstay

The standing rigging running from the stern to the top of the mast, keeping the mast from falling forward.

Ballast

Weight in the keel of a boat that provides stability.

Batten

A thin slat that slides into a pocket in the leech of a sail, helping it hold its shape.

Beam

The width of a boat at its widest point.

Beam reach

(Point of sail) sailing in a direction at approximately $90\,degrees$ to the wind.

Bearing

The direction from one object to another expressed in compass degrees.

Beating

A course sailed upwind.

Bilge

The lowest part of the boat's interior, where water on board will collect.

Bitter end

The end of a line.

Block

A pulley on a boat.

Bolt rope

The rope sewn into the foot and luff of some mainsails and the luff of some jibs by which the sails are attached to the boat.

Boom

The spar extending directly aft from the mast to which the foot of the mainsail is attached.

Boom vang

A block and tackle system which pulls the boom down to assist sail control.

Bowline

A knot designed to make a loop that will not slip and can be easily untied.

Broach

An uncontrolled rounding up into the wind, usually from a downwind point of sail.

Broad reach

(Point of sail) sailing in a direction with the wind at the rear corner of the boat (approximately $135\,degrees$ from the bow).

Bulkhead

A wall that runs athwartships on a boat, usually providing structural support to the hull.

By the lee

Sailing on a run with the wind coming over the same side of the boat as the boom.

Can

An odd-numbered, green, flat-topped buoy marking the left side of a channel as you return to port.

Chainplates

Strong metal plates which connect the shrouds to the boat.

Clew

The lower, aft corner of a sail; the clew of the mainsail is held taut by the outhaul.

Close-hauled

The point of sail that is closest to the wind.

Close reach

(Point of sail) sailing in a direction with the wind forward of the beam (about $70\,degrees$ from the bow).

Companionway

The steps leading from the cockpit or deck to the cabin below.

Cunningham

A line running through a grommet about $8\,inches$ up from the tack of a mainsail that is used to tighten the luff of the sail.

Displacement

The weight of a boat; therefore the amount of water it displaces.

Downhaul

A line used to pull down on the movable gooseneck on some boats to tighten the luff of the mainsail.

Draft

The depth of a boat's keel from the water's surface.

Fathom

A measurement of the depth of water where one fathom equals $6\,feet$.

Fetch

A course on which a boat can make its destination without having to tack.

Float Plan

A brief description of intended boating activity left with a trusted person, including vessel name, persons onboard, destination, planned return time, and cell phone number.

Freeboard

The height of the hull above the water's surface.

Furl

To fold or roll up a sail.

Genoa

A large jib whose clew extends aft of the mast.

Give-way vessel

The vessel required to give way to another boat when they may be on a collision course.

Glide zone

The distance a sailboat takes to coast to a stop.

Gooseneck

The strong fitting that connects the boom to the mast.

Ground tackle

The anchor and rode (chain and line).

Gunwale

The edge of the deck where it meets the topsides.

Halyard

A line used to hoist or lower a sail.

Head-to-wind

The course of the boat when the bow is dead into the wind.

Heave-to

To hold one's position in the water by using the force of the sails and rudder to counter one another.

Heel

The lean of a boat caused by the wind.

Hull speed

The theoretical maximum speed of a sailboat determined by the length of its waterline.

In irons

A boat that is head-to-wind, making no forward headway.

Jibe

To change direction of a boat by steering the stern through the wind.

Keel

The heavy vertical fin beneath a boat that helps keep it upright and prevents it from slipping sideways in the water.

Knot

One nautical mile per hour.

Leech

The aft edge of a sail.

Leeward

The direction away from the wind (where the wind is blowing to).

Leeway

Sideways slippage of the boat in a direction away from the wind.

Luff

The forward edge of a sail, or the fluttering of a sail caused by aiming too close to the wind.

MAYDAY

An internationally recognized distress signal, only used in cases of imminent danger when immediate assistance is needed to save a life.

Nautical mile

A distance of $6076\,feet$, equaling one minute of the earth's latitude.

No-Sail (No-Go) Zone

An area into the wind in which a boat cannot produce power to sail.

Nun

A red, even-numbered, cone-shaped buoy marking the right side of a channel as you return to port.

Outhaul

The controlling line attached to the clew of a mainsail used to tension the foot of the sail.

Pintle

Small metal extensions on a rudder that slide into a gudgeon on the transom.

PIW

Abbreviation for "Person in Water" in a man overboard emergency.

Port

The left side of a boat when facing forward.

Rode

Line and chain attached from the boat to the anchor.

Run

(Point of sail) sailing with the wind coming directly behind the boat.

Schooner

A two-masted boat whose foremast is usually shorter than its mainmast.

Scope

The ratio of the amount of anchor rode deployed to the distance from the bow to the bottom.

Sloop

A single-masted sailboat with mainsail and headsail.

Spinnaker

A large billowing headsail used when sailing downwind.

Standing rigging

The permanent rigging (usually wire) of a boat, including the forestay, backstay, and shrouds.

Stand-on vessel

The vessel or boat with the right-of-way.

Starboard

The right side of the boat when looking from the stern toward the bow.

Stem

The forward tip of the bow.

Tack (Verb)

To change direction by turning the bow through the wind.

Tack (Noun)

The lower forward corner of a sail.

Telltales

Pieces of yarn or sailcloth attached to sails to indicate proper trim, or wind direction indicators on standing rigging.

Tiller

A long handle, extending into the cockpit, which directly controls the rudder.

Transom

The vertical surface of the stern.

True wind

The actual speed and direction of the wind when standing still.

Underway

To be under the power of sail or engine.

Weather helm

The boat's tendency to head up toward the wind, which occurs when a sailboat is overpowered.

Westerly Wind

Wind that comes out of the West and blows toward the East.

Windward

Toward the wind.

Wing-and-wing

Sailing downwind with the jib set on the opposite side of the mainsail.