Marine Terminology

Pronunciationaft

Toward the stern.

Example: Bring the boat hook aft after the dock line is secure.
Related: Stern Forward

Air draft

Pronunciationair draft

The height of the boat above the waterline, usually to the masthead or highest fixed point.

Example: Air draft matters before passing under bridges.
Related: MastBridge clearance

AIS

PronunciationA-I-S

Automatic Identification System, which broadcasts and receives vessel identity, position, course, and speed data.

Example: AIS helps identify traffic, but visual lookout and radar still matter.
Related: VHF Course over ground

Alternator

Pronunciationalternator

An engine-driven generator that charges batteries while the engine is running.

Example: Monitor alternator output after installing a larger battery bank.
Related: Battery bank Shore power

Amidships

Pronunciationuh-MID-ships

Near the middle of the boat, lengthwise or across the beam.

Example: Store the heavy gear amidships to reduce trim problems.
Related: Beam Trim

Anchor

Pronunciationanchor

A device lowered to the seabed to hold the boat in place.

Example: Choose an anchor size and type suitable for the boat and bottom conditions.
Related: Rode Scope Windlass

Apparent wind

Pronunciationapparent wind

The wind felt onboard, combining true wind with wind created by the boat moving.

Example: Sails are trimmed to apparent wind while underway.
Related: True wind Point of sail

B

Ballast

Pronunciationballast

Weight placed low in the boat, often in the keel, to improve stability.

Example: Ballast ratio is one clue to a sailboat stability profile.
Related: Keel Displacement

Barometer

Pronunciationbarometer

An instrument that measures atmospheric pressure for weather awareness.

Example: A falling barometer can warn of approaching unsettled weather.
Related: SquallWeather window

Battery bank

Pronunciationbattery bank

A group of batteries wired to supply onboard electrical loads.

Example: Separate house and start battery banks to protect engine starting power.
Related: Alternator Inverter Shore power

Beam

Pronunciationbeam

The maximum width of the boat.

Example: Beam affects berth fit, interior volume, and stability character.
Related: Amidships LOA

Beam reach

Pronunciationbeam reach

A point of sail with wind coming roughly across the side of the boat.

Example: Many boats feel balanced and quick on a beam reach.
Related: Close reach Broad reach

Bear away

Pronunciationbear away

Turn the bow away from the wind.

Also called: Fall off
Example: Bear away ten degrees to build speed after the tack.
Related: Head up Point of sail

Bearing

Pronunciationbearing

The direction from one position to another, usually expressed in degrees.

Example: Take a bearing on the lighthouse to confirm the boat position.
Related: Heading Waypoint

Berth

Pronunciationberth

A place where a boat is moored or docked; also a sleeping space onboard.

Example: Confirm berth length, beam limit, and shore power before arrival.
Related: Slip Mooring

Bilge

Pronunciationbilge

The lowest interior area of the hull where water can collect.

Example: A clean bilge makes leaks easier to spot.
Related: Bilge pump Hull

Bilge pump

Pronunciationbilge pump

A pump used to remove water from the lowest interior part of the hull.

Example: Test the automatic bilge pump and float switch before leaving the dock.
Related: Bilge Seacock

Boom

Pronunciationboom

The horizontal spar attached to the mast along the foot of the mainsail.

Example: Keep heads clear when the boom moves during a tack or gybe.
Related: Mainsail Vang Preventer

Bow

PronunciationBOW (rhymes with now)

The forward end of the boat.

Example: Move the fender toward the bow before we enter the slip.
Related: Stern Forward

Bow roller

Pronunciationbow roller

A roller fitting at the bow that guides anchor rode and stores the anchor.

Example: Check the bow roller pin before a long passage.
Related: Anchor Bow

Bridle

Pronunciationbridle

A two-legged line arrangement that shares load between two attachment points.

Example: A catamaran often uses an anchor bridle to reduce sailing at anchor.
Related: Snubber Anchor

Broad reach

Pronunciationbroad reach

A point of sail with wind coming from behind the beam.

Example: Ease sails out for a broad reach and watch for accidental gybe risk.
Related: Run Preventer

C

Cabin

Pronunciationcabin

An enclosed living, storage, or working space inside the boat.

Example: The forward cabin has the main berth on this model.
Related: Companionway

Chain

Pronunciationchain

Metal anchor rode that adds weight, abrasion resistance, and a low pull angle.

Example: All-chain rode can help the anchor stay set in a crowded anchorage.
Related: Rode Windlass Snubber

Chartplotter

Pronunciationchartplotter

An electronic navigation display that shows charts, position, routes, and vessel data.

Example: Do not rely only on the chartplotter in shallow or poorly surveyed water.
Related: Waypoint AIS Course over ground

Chock

Pronunciationchock

A deck fitting that guides dock, mooring, or anchor lines.

Example: Inspect chocks for sharp edges that can chafe mooring lines.
Related: Fairlead Cleat

Chop

Pronunciationchop

Short, steep, irregular waves often created by local wind or wind against current.

Example: Expect chop where the afternoon breeze meets an outgoing tide.
Related: Swell Fetch

Cleat

Pronunciationcleat

A fitting used to secure a line.

Example: Finish the dock line with a clean cleat hitch.
Related: Dock lineCleat hitch

Close reach

Pronunciationclose reach

A point of sail between close-hauled and a beam reach.

Example: A close reach is often faster and easier than pinching close-hauled.
Related: Beam reach Close-hauled

Close-hauled

Pronunciationclose-hauled

Sailing as close to the wind as the boat can efficiently sail.

Example: Trim sails in tight when sailing close-hauled.
Related: No-go zoneBeat

Cockpit

Pronunciationcockpit

The recessed working area where crew often steer, trim sails, and operate controls.

Example: The mainsheet and winches are led back to the cockpit.
Related: Helm Companionway

COLREGs

PronunciationKOHL-regs

International collision regulations that define navigation rules between vessels.

Also called: Rules of the road
Example: A sailing vessel under engine is treated as power-driven under the rules.
Related: LookoutStand-on vessel

Companionway

Pronunciationcompanionway

The entrance between cockpit or deck and the cabin below.

Example: Close the companionway hatch before spray starts coming aboard.
Related: Cabin Cockpit

Course over ground

PronunciationC-O-G

The actual direction the boat is moving over the earth.

Also called: COG
Example: Compare heading and course over ground to understand current or leeway.
Related: Heading Speed over ground

Cunningham

PronunciationKUHN-ing-ham

A control that tensions the luff of the mainsail.

Example: Add cunningham tension as wind builds to flatten the sail.
Related: Mainsail Luff

Current

Pronunciationcurrent

Water movement in a direction, often caused by tide, river flow, or ocean circulation.

Example: Account for cross-current before turning into the slip.
Related: Tide Course over ground

Cutless bearing

Pronunciationcutless bearing

A water-lubricated bearing that supports a propeller shaft near the hull exit.

Example: Side play at the shaft can indicate cutless bearing wear.
Related: Shaft Propeller

D

Deck

Pronunciationdeck

The upper working surface of the boat.

Example: Keep loose gear off the deck before leaving the dock.
Related: CockpitCabin top

Displacement

Pronunciationdisplacement

The weight of water displaced by the boat, commonly used as an approximate boat weight.

Example: A heavier displacement boat may feel steadier but needs more power to accelerate.
Related: Ballast Hull

Dock line

Pronunciationdock line

A line used to secure a boat to a dock or berth.

Example: Set bow, stern, and spring lines before leaving the boat.
Related: Spring line Cleat

Draft

Pronunciationdraft

The depth of the boat below the waterline.

Example: Check draft against charted depth before entering a shallow anchorage.
Related: KeelWaterline

E

Ease

Pronunciationease

Let a line out in a controlled way.

Example: Ease the sheet two inches to reduce heel.
Related: Trim Sheet

F

Fairlead

Pronunciationfairlead

A fitting or opening that guides a line along a fair path.

Example: Lead the spring line through a fairlead to reduce chafe.
Related: Chock Dock line

Fender

Pronunciationfender

A cushion placed between boat and dock or another vessel to prevent damage.

Example: Set fenders at the widest part of the hull before docking.
Related: Dock line Slip

Fetch

Pronunciationfetch

The distance wind blows over open water, allowing waves to build.

Example: A long fetch across the bay can make the lee shore rough.
Related: Chop Lee shore

Forward

Pronunciationforward

Toward the bow.

Example: Step forward carefully and keep one hand on the rail.
Related: Bow Aft

Freeboard

Pronunciationfreeboard

The vertical distance between the waterline and the deck edge or hull side.

Example: Higher freeboard can add interior volume but catches more wind at the dock.
Related: WaterlineHull

Freshwater tank

Pronunciationfreshwater tank

A tank that stores potable or domestic water for onboard use.

Example: Clean the freshwater tank before the cruising season.
Related: Galley Head

Furling

Pronunciationfurling

Rolling a sail around a stay, mast, or boom for storage or sail reduction.

Example: Keep light tension on the sheet while furling the headsail.
Related: Headsail Reef

G

Galley

Pronunciationgalley

The cooking and food preparation area onboard.

Example: Secure galley drawers and stove gimbals before sailing.
Related: Cabin Freshwater tank

Genoa

PronunciationJEN-oh-uh

A larger overlapping headsail that extends aft of the mast.

Example: A large genoa adds power in light air but can be harder to tack.
Related: Headsail Jib

Gust

Pronunciationgust

A brief increase in wind speed.

Example: Ease the mainsheet during a strong gust to reduce heel.
Related: Squall Apparent wind

Gybe

Pronunciationjibe

A maneuver turning the stern through the wind so the boom crosses sides.

Also called: Jibe
Example: Stand by to gybe, then control the mainsheet as the boom comes across.
Related: Tack Preventer Run

H

Halyard

PronunciationHAL-yerd

A line used to raise, lower, or tension a sail.

Example: Ease the main halyard a few centimeters before tying in the reef.
Related: Line Mainsail

Head

Pronunciationhead

The marine toilet or the compartment containing it.

Example: Show new crew how to operate the head before leaving the dock.
Related: Holding tank

Head up

Pronunciationhead up

Turn the bow toward the wind.

Example: Head up slightly to reduce pressure before trimming again.
Related: Bear away Luff

Heading

Pronunciationheading

The direction the bow is pointing.

Example: The heading can differ from the course over ground when current or leeway is present.
Related: Course over ground Leeway

Headsail

Pronunciationheadsail

Any sail set forward of the mast.

Example: Partially furl the headsail before entering the channel.
Related: Jib Genoa Furling

Heave-to

Pronunciationheave-to

A controlled stopped or slow-drifting sailing configuration using backed headsail, rudder, and mainsail balance.

Example: Heave-to to settle the boat before reefing or waiting for a squall to pass.
Related: Headsail Rudder

Helm

Pronunciationhelm

The steering position or the steering control itself.

Example: Take the helm while I reef the mainsail.
Related: Wheel Tiller Rudder

Holding tank

Pronunciationholding tank

A tank that stores toilet waste until it can be pumped out or legally discharged.

Example: Check holding tank capacity before a multi-day cruise.
Related: Head

Hull

Pronunciationhull

The watertight body of the boat that provides buoyancy and shape.

Example: A surveyor checks the hull for damage, moisture, and previous repairs.
Related: Deck Keel Freeboard

I

Impeller

Pronunciationimpeller

A flexible pump rotor that moves cooling water through many marine engines.

Example: Replace the raw-water impeller if the engine overheats or flow drops.
Related: Raw-water coolingEngine

In irons

Pronunciationin irons

Stalled head-to-wind with sails luffing and little steering control.

Example: Back the jib or bear away to recover from being in irons.
Related: No-go zone Luff

Inboard

Pronunciationinboard

An engine mounted inside the hull, usually driving a shaft or saildrive.

Example: Check inboard engine access before committing to a maintenance plan.
Related: Shaft Propeller

Inverter

Pronunciationinverter

A device that converts battery DC power into AC power for household-style loads.

Example: Large inverter loads can drain a battery bank quickly.
Related: Battery bank Shore power

J

Jackline

Pronunciationjackline

A strong line or webbing run along deck so crew can clip in with a tether.

Example: Rig jacklines before the weather turns, not after the deck is wet.
Related: PFDTether

Jib

Pronunciationjib

A triangular headsail set ahead of the mast, usually smaller than a genoa.

Example: Trim the jib sheet after the tack.
Related: Headsail Sheet

K

Keel

Pronunciationkeel

The underwater fin, ballast structure, or centerline backbone that helps resist sideways drift and supports stability.

Example: The pre-purchase survey should inspect keel bolts and fairing condition.
Related: Draft Ballast Leeway

Knot

Pronunciationknot

A speed unit of one nautical mile per hour.

Example: A current of two knots can strongly affect docking and route timing.
Related: Nautical mile Speed over ground

L

Lee shore

Pronunciationlee shore

A shore downwind of the boat, where wind or waves may push the boat toward land.

Example: Avoid anchoring close to a lee shore when wind is forecast to build.
Related: Leeway Fetch

Leeward

PronunciationLEE-ward or LOO-ward

The side or direction away from the wind.

Also called: Lee side
Example: Keep clear of the leeward rail when the boat is heeled.
Related: Windward Leeway

Leeway

Pronunciationleeway

Sideways drift caused by wind pushing the boat away from its heading.

Example: Allow for leeway when sailing close to a lee shore.
Related: Keel Course over ground

Lifeline

Pronunciationlifeline

Wire, rope, or rail system along deck edges that helps keep crew onboard.

Example: Do not use a lifeline as a primary towing or lifting point.
Related: StanchionJackline

Line

Pronunciationline

Rope with a specific job onboard.

Example: Coil each line after use so it runs freely when needed.
Related: Halyard Sheet Dock line

LOA

PronunciationL-O-A

Length overall, usually the total length of the boat from forward to aft extremity.

Also called: Length overall
Example: A marina may price the berth by LOA.
Related: LWL Beam

Luff

Pronunciationluff

The leading edge of a sail, or the act of a sail flapping because it is not trimmed or aligned with the wind.

Example: Ease until the luff just starts to flutter, then trim slightly.
Related: Trim Head up

LWL

PronunciationL-W-L

Length at the waterline.

Also called: Waterline length
Example: Longer LWL can improve potential displacement hull speed.
Related: LOAHull speed

M

Mainsail

Pronunciationmainsail

The primary sail set behind the mast on most fore-and-aft rigs.

Example: Reef the mainsail early if gusts are producing heavy helm.
Related: Boom Reef Traveller

Mast

Pronunciationmast

The vertical spar that supports sails and rigging.

Example: Check the mast track and halyard sheaves before hoisting.
Related: Boom Shroud Stay

MOB

PronunciationM-O-B

Man overboard, meaning a person has gone over the side and recovery action is needed.

Also called: Person overboard
Example: Call MOB, point continuously, and mark the position immediately.
Related: PFD VHF

Mooring

Pronunciationmooring

A fixed anchoring system or the act of securing a boat to one.

Example: Pick up the mooring pennant from the bow, not the stern.
Related: PennantBerth

N

Nautical mile

Pronunciationnautical mile

A marine distance unit equal to one minute of latitude, about 1.852 kilometers.

Also called: NM
Example: The anchorage is six nautical miles from the harbor entrance.
Related: Knot Course over ground

No-go zone

Pronunciationno-go zone

The wind angle too close to the wind for a sailboat to keep sailing efficiently.

Example: If the bow enters the no-go zone and stalls, the boat may end up in irons.
Related: In irons Close-hauled

O

Outboard

Pronunciationoutboard

A self-contained engine mounted outside the transom or on a bracket.

Example: Tilt the outboard clear of the water when the dinghy is stored.
Related: Transom Propeller

Outhaul

Pronunciationouthaul

A control that tensions the foot of the mainsail along the boom.

Example: Ease the outhaul slightly in light wind for more sail shape.
Related: Boom Mainsail

P

Painter

Pronunciationpainter

A line attached to the bow of a dinghy or small boat.

Example: Secure the tender painter to a strong cleat, not a lifeline.
Related: Bow Dock line

PFD

PronunciationP-F-D

Personal flotation device worn to help keep a person afloat.

Also called: Life jacket
Example: Wear a properly fitted PFD when conditions, rules, or skipper policy require it.
Related: MOB Jackline

Point of sail

Pronunciationpoint of sail

The boat angle relative to the true wind direction.

Example: Call the point of sail before adjusting trim.
Related: Close-hauled Beam reach Run

Port

Pronunciationport

The left side of the boat when facing the bow.

Example: Put the red dock line on the port bow cleat.
Related: StarboardPort tack

Preventer

Pronunciationpreventer

A line rigged to reduce the risk of an accidental boom gybe.

Also called: Boom preventer
Example: Rig a preventer on a long downwind leg in rolling seas.
Related: Boom Gybe Run

Propeller

Pronunciationpropeller

The rotating blades that convert engine power into thrust through the water.

Also called: Prop
Example: A fouled propeller can cause vibration and poor acceleration.
Related: Shaft Inboard Outboard

Q

Q flag

PronunciationQ flag

The yellow international code flag used to request pratique or signal health-clearance status when entering some ports.

Also called: Yellow flag, Quebec flag
Example: A vessel arriving from offshore may fly the Q flag until cleared by the port authority.
Related: VHF

Quarter

Pronunciationquarter

Either after side of the boat, between the beam and the stern.

Example: The following sea was coming over the starboard quarter.
Related: Stern Beam Transom

Quartering sea

Pronunciationquartering sea

Waves approaching from an aft quarter rather than directly ahead, abeam, or astern.

Example: A quartering sea can make steering more active on a downwind passage.
Related: Quarter Sea state Swell

Quay

Pronunciationkey

A solid waterfront structure where boats or ships can berth alongside.

Also called: Wharf
Example: Confirm fender height before coming alongside a high quay wall.
Related: Berth Slip Dock line

R

Raw-water cooling

Pronunciationraw-water cooling

A system that uses outside water to remove engine heat directly or through a heat exchanger.

Example: Check raw-water flow at the exhaust after starting the engine.
Related: Impeller Seacock

Reef

Pronunciationreef

To reduce sail area so the boat carries less power in stronger wind.

Example: Put the first reef in before the boat becomes hard to steer.
Related: MainsailReefing line

Rode

Pronunciationrode

The line, chain, or combination connecting the anchor to the boat.

Example: Lay out enough rode before setting the anchor.
Related: Anchor Chain Scope

Rudder

Pronunciationrudder

The underwater steering surface that turns the boat as water flows past it.

Example: Heavy weather helm may indicate too much sail or poor trim before it is a rudder problem.
Related: Helm Tiller Wheel

Run

Pronunciationrun

Sailing with the wind coming from behind the boat.

Also called: Running
Example: A deep run can be comfortable but needs careful boom control.
Related: Broad reach Preventer

S

Sail area

Pronunciationsail area

The measured area of the sails, often listed for main and foretriangle or standard working sails.

Example: Sail area helps compare power between boats of similar displacement.
Related: Mainsail Headsail

Saildrive

Pronunciationsaildrive

A compact drive leg through the hull that connects an inboard engine to a propeller.

Example: Inspect the saildrive diaphragm at the service interval recommended by the manufacturer.
Related: Inboard Propeller

Scope

Pronunciationscope

The ratio of anchor rode length deployed to water depth and bow height.

Example: More scope usually improves holding but requires more swinging room.
Related: Anchor RodeSwinging room

Sea state

Pronunciationsea state

The condition of the sea surface, including wave height, period, and steepness.

Example: Sea state can matter more to comfort than wind speed alone.
Related: Swell Chop

Seacock

Pronunciationseacock

A valve mounted on a through-hull fitting to control water entering or leaving the boat.

Example: Exercise seacocks regularly so they can close in an emergency.
Related: Through-hull Bilge pump

Shaft

Pronunciationshaft

The rotating metal rod that transfers engine power to the propeller.

Example: Shaft alignment affects vibration and cutless bearing wear.
Related: Propeller Cutless bearing

Sheet

Pronunciationsheet

A line used to trim a sail in or out.

Example: Ease the mainsheet to reduce heel in a gust.
Related: Trim Winch

Shore power

Pronunciationshore power

Electrical power supplied from the dock to the boat.

Example: Confirm shore power voltage and cord condition before connecting.
Related: Battery bank Inverter

Shroud

Pronunciationshroud

Standing rigging that supports the mast from side to side.

Example: Inspect shroud terminals for cracks or corrosion.
Related: StayStanding rigging

Slip

Pronunciationslip

A dock space where a boat is berthed between finger piers or alongside a dock.

Example: Rig fenders before entering the slip.
Related: Berth Fender Dock line

Snubber

Pronunciationsnubber

A stretchy line used to absorb shock loads from an anchor chain or mooring.

Example: Set a snubber so the windlass is not carrying the anchor load overnight.
Related: Chain Bridle

Speed over ground

PronunciationS-O-G

The boat speed measured over the earth rather than through the water.

Also called: SOG
Example: A favorable current can make SOG higher than speed through water.
Related: Course over ground

Spinnaker

PronunciationSPIN-uh-ker

A large, light sail used for downwind or reaching angles.

Example: Set the spinnaker only after the crew is clear on sheets and retrieval.
Related: Run Broad reach

Spreader

Pronunciationspreader

A spar projecting from the mast that changes the angle of the shrouds.

Example: Look at the spreader tips for wear where the sail may touch.
Related: Mast Shroud

Spring line

Pronunciationspring line

A dock line led diagonally to prevent the boat moving forward or aft.

Example: A forward spring can hold the boat while the stern swings out.
Related: Dock line Cleat

Squall

Pronunciationsquall

A sudden, often strong increase in wind, sometimes with rain or reduced visibility.

Example: Reef early if squalls are visible upwind.
Related: Gust Reef

Starboard

Pronunciationstarboard

The right side of the boat when facing the bow.

Example: The green navigation light is on the starboard side.
Related: PortStarboard tack

Stay

Pronunciationstay

Standing rigging that supports the mast fore and aft.

Example: The forestay supports the headsail furling system.
Related: ForestayBackstayShroud

Stern

Pronunciationstern

The aft end or back of the boat.

Example: The swim platform is mounted at the stern.
Related: Bow Aft Transom

Swell

Pronunciationswell

Longer-period waves that have traveled away from their generating wind.

Example: A low swell can still make an anchorage uncomfortable if it rolls in from the side.
Related: Sea state Chop

T

Tack

Pronunciationtack

A maneuver turning the bow through the wind; also the side the wind is coming from while sailing.

Example: On port tack, the wind is coming over the port side.
Related: Gybe Port Starboard

Through-hull

Pronunciationthrough-hull

A fitting that passes through the hull for water intake, discharge, instruments, or drains.

Example: Every below-waterline through-hull should have a working seacock.
Related: Seacock Hull

Tide

Pronunciationtide

The periodic rise and fall of sea level caused mainly by the moon and sun.

Example: Enter the shallow channel near high tide.
Related: CurrentTide table

Tiller

Pronunciationtiller

A lever attached to the rudder stock for steering.

Example: Push the tiller to port and the bow turns starboard.
Related: Helm Rudder

Topping lift

PronunciationTOP-ing lift

A line or support that holds the boom up when the mainsail is not carrying it.

Example: Tension the topping lift before dropping the mainsail.
Related: Boom Mainsail

Transom

Pronunciationtransom

The flat or shaped surface across the stern of many boats.

Example: The swim ladder folds into the transom.
Related: SternSwim platform

Traveller

Pronunciationtraveller

A track and car system that adjusts the mainsheet attachment point.

Example: Drop the traveller to leeward to reduce heel while keeping mainsail shape.
Related: MainsailMainsheet

Trim

Pronunciationtrim

Pull in or adjust a sail control to set sail angle or shape.

Example: Trim the jib until the telltales stream evenly.
Related: Sheet Ease

True wind

Pronunciationtrue wind

The wind speed and direction relative to the earth, independent of boat motion.

Example: True wind is useful for weather decisions and route planning.
Related: Apparent wind

U

Under way

Pronunciationunder way

A vessel state meaning the boat is not at anchor, made fast to shore, or aground.

Also called: Underway
Example: Navigation rules can apply differently once a vessel is under way.
Related: COLREGs Heading

Unstayed mast

Pronunciationunstayed mast

A mast designed to stand without shrouds or stays.

Example: An unstayed mast keeps the rig simpler but changes spar and hull loads.
Related: Mast Shroud Stay

Upwind

Pronunciationupwind

Toward the direction the wind is coming from.

Example: The crew moved upwind before the tack to balance the boat.
Related: Windward Leeward Point of sail

V

Vang

Pronunciationvang

A control that pulls the boom downward and controls mainsail twist.

Also called: Kicker
Example: Ease the vang before bearing away in light wind.
Related: Boom Mainsail

VHF

PronunciationV-H-F

Very high frequency marine radio used for vessel communication and distress calls.

Example: Use the VHF to call the marina or monitor safety traffic.
Related: MOBMayday

Visibility

Pronunciationvisibility

The distance at which objects can be seen clearly.

Example: Reduced visibility requires slower speed, sound signals, and careful lookout.
Related: COLREGs VHF

W

Waypoint

Pronunciationwaypoint

A saved navigation position used as a destination, turn point, or reference.

Example: Set a waypoint outside the harbor entrance before leaving the marina.
Related: Chartplotter Course over ground

Wheel

Pronunciationwheel

A circular steering control connected to the rudder system.

Example: Center the wheel before engaging the autopilot.
Related: Helm Rudder

Winch

Pronunciationwinch

A mechanical drum that gives purchase for trimming loaded lines.

Example: Keep fingers clear and do not override the sheet on the winch.
Related: Sheet Halyard

Windlass

Pronunciationwindlass

A powered or manual device used to raise and lower the anchor rode.

Example: Use the engine to move toward the anchor instead of pulling the boat with the windlass.
Related: Anchor Chain

Windward

Pronunciationwindward

The side or direction from which the wind is coming.

Example: Move weight to windward when the boat heels in stronger breeze.
Related: LeewardHeel

X

Xebec

PronunciationZEE-bek

A historic Mediterranean sailing vessel, often rigged with lateen sails.

Example: A xebec is useful as a historical rig reference, not a modern cruising category.
Related: MastSail plan

XTE

PronunciationX-T-E

Cross-track error, the sideways distance between the boat position and the intended route line.

Also called: Cross-track error
Example: Rising XTE can show that current is setting the boat away from the planned track.
Related: Waypoint Course over ground

Y

Yard

Pronunciationyard

A spar set across a mast to support or spread a sail, especially on square rigs.

Example: Square-sail vessels carry yards rather than a fore-and-aft boom for each sail.
Related: MastSail plan

Yaw

Pronunciationyaw

Side-to-side rotation of the bow around the vertical axis.

Example: A boat may yaw at anchor in gusty wind or following seas.
Related: Heading Rudder

Yawl

Pronunciationyawl

A two-masted sailing rig with a small mizzen mast stepped aft of the rudder post.

Example: A yawl can look similar to a ketch, but the mizzen is farther aft.
Related: Mast Mainsail

Z

Zinc anode

Pronunciationzink AN-ode

A sacrificial metal anode fitted to reduce galvanic corrosion of underwater metals.

Also called: Sacrificial anode, Anode
Example: Replace zinc anodes before they are mostly consumed.
Related: Propeller Shaft

Zone of confidence

Pronunciationzone of confidence

A chart-quality rating that describes the survey accuracy and reliability of charted data.

Also called: ZOC, CATZOC
Example: Check the zone of confidence before relying on charted depth in remote waters.
Related: Chartplotter Waypoint

Zulu time