Abeam: Directly to the side of the boat.
About: On the opposite tack.
Aft: At or near the stern.
Alee: To the leeward side.
Aloft: Above the deck.
Anchor: A device shaped so as to grip the bottom, secured to a line from the boat to hold it in the desired position.
Apparent wind: The direction and speed of the wind felt by the crew. Combination of the true wind and that created by the motion of the boat.
Astern: Behind the boat.
Backstay: Any single wire supporting the mast from the stern.
Ballast: Weight placed in the bottom of the boat to give it stability.
Batten: Thin wooden strips fitted into pockets for stiffening the leech of a sail.
Beam: Measurement of the width of a boat.
Beam reach: Sailing with the wind coming across the boat’s beam.
Beam wind: A wind at right angles to a boat’s course.
Bear away: To steer the boat away from the wind.
Bearing: The compass (magnetic) direction from one object to another.
Beat: Sailing against the wind by tacking (sailing a zigzag course towards the wind).
Beating to windward: To sail to windward close-hauled, tacking as you go, to reach an objective to windward.
Bend: To connect two ropes with a knot.
Bilge: The very lowest part of a boat’s interior, where water is most likely to collect.
Block: A pulley.
Bollard: A short heavy post on a pier or boat used for fastening docking lines.
Boom: Spar that takes the foot of a sail.
Bow: The forward part of a boat.
Broach: Turn sideways to wind and the surf.
Broad reach: The point of sailing between a beam reach and a run, when the wind blows over the quarter.
Buoy: Floating navigational marker.
Cabin: A room on a boat for passengers and crew
Cabin sole: The floor of a cabin
Capsize: To overturn.
Cast off To let go of a line when leaving the dock or mooring; to ease sheets.
Center of Effort (COE): The point at which all the forces acting on the sails are concentrated.
Center of Lateral resistance (CLR): The underwater center of pressure about which a boat pivots when changing course.
Centerboard: Retractable keel to stop a boat’s leeward drift.
Chain Plate: Metal fitting bolted to the side of a boat to hold the ends of stays and shrouds to support the rigging.
Cleat: Fitting to which a line is secured, without knotting.
Clew: Aft bottom corner of a sail, where the foot and leech meet.
Close-Hauled: Sailing close to the wind with sails pulled in.
Close Reach: The point of sailing between close-hauled and a beam reach, when the wind blows forward of the beam.
Cockpit: The space at a lower level than the deck in which the tiller or wheel is located, may be center or aft.
Come About: To change course so as to be sailing at the same angle but with the wind on the other side.
Course: The direction in which a vessel is steered, usually given in degrees.
Cutter: Single-masted fore-and-aft boat having an inner staysail and outer jib.
Daggerboard: A board normally attached to dinghies to reduce sideways drift. Released vertically, unlike a centerboard, which lifts around a pin.
Dead Ahead: Straight forward direction.
Dead Astern: Straight aft direction.
Deadlight: Fixed light in a cabin’s roof.
Deck: Solid covering over a hull, does not always cover all of it.
Depression: Low-pressure area in meteorology.
Dew point: The point of temperature and air pressure at which water vapor forms mist or fog.
Dinghy: A small to medium sized, open boat.
Dismasting: If the mast breaks and goes off. Sucks badly.
Displacement: The amount of water that is displaced by a boat and thereof – according to Archimedes – as heavy as the boat
Dock: A protected area that is normally part of a port where boats can be moored.
Dodger: A simple, protective screen that protects the cockpit from wind and water; also used for cloth that is used for weather protection of boats or accessories.
Downhaul: The rope that is used to pull a sail down.
Downwind: All courses further away from the wind than a beam reach.
Draft: The depth of water that a boat draws.
Drift: Strength of a tidal current.
Ease: To let out.
Ebb: A receding tide or current.
EP: Estimated Position, a value plotted on a map or chart in temporal intervals.
EPIRB: Emergency Position Indication Radio Beacon. Radio signaling aid that allows the transmission of emergency position calls.
Fairlead: A fitting that is used to direct or re-direct lines and ropes.
Falling Off: Turn away from the direction of the wind.
Fathom: Nautical measurement for the depth of water where one fathom equals to six feet.
Fender: A cushion-like thing that is placed along the hull to protect it from collision with other boats, pier walls or cliffs to prevent damage normally when mooring.
Figure Eight Knot: A common knot that is often used to prevent lines and ropes from slipping through a fitting.
Fin Keel: A single keel that is centrally located and ballasted.
Flare: An emergency signal.
Flood: A current moving towards land.
Fluke: The barbs or hooks of anchors.
Following Sea: An overtaking sea coming from astern.
Foot: The bottom end of a sail.
Foremast: The mast that is most forward on a boat.
Foresail: The lowest square sail on the most forward mast.
Forestay: The wiring that supports the mast and keeps it from falling backwards. Leads from masthead to bowsprit or foredeck.
Foretriangle: The triangle that is formed by the forestay, mast and deck.
Fouled: If gear or parts of the boat are jammed, messed up or dirty.
Foul Weather Gear: Clothing and accessories that are designed to accommodate needs that arise from bad weather issues
Freeboard: The area from the deck to the waterline.
Freer: A change in the wind direction to the aft of a boat
Galley: The cooking facility on a boat; in larger yachts normally called kitchen.
Gangway: The part of a ship or large yacht where passengers and crew board or disembark.
Gear: All equipment used for sailing except the boat itself; rather a commercial than a nautical term.
Gennaker: A sail that is a hybrid between a spinnaker and a genoa.
Genoa: A large headsail, which overlaps the mast and often meets the deck with its foot.
Gimbals: A fitting that moves in a way that keeps delicate or potentially dangerous objects in an upright position even in the case of the boat heeling; e.g. gimbaled stove or compass.
Gloves: Sailing gloves protect hands of competitive sailors and allow the fast handling of wires and lines.
Gooseneck: A universal joint fitting that links the boom with the mast.
GPS: Global Positioning System.
Ground Tackle: Anchor and all related anchoring equipment such as warp or capstan used to secure a boat to her mooring.
Gunwale: Upper edge of the side of the hull.
Guy: A wire or line controlling the spinnaker pole.
Halyards: Ropes or wires for lifting or lowering sails and associated spars.
Hanks: The metal clips that attach a sail to a forestay.
Hatch: An opening in the deck to enter the space below it.
Head: The top-corner of a sail; in larger yachts also the toilet or bathroom and washing facility.
Headway: Forward motion of a boat.
Heading: The direction into which a boat is steered, the intended course.
Heads: Toilet facility on a boat.
Headsails: All sails that are used forward of the foremast.
Heel: The tilting of a boat into an angle whilst it sails.
Helm: The wheel or tiller through which you control the rudder.
Helmsman: The Sailor that steers the vessel.
Hitch: A common knot that is often used to secure a rope to another one – or an object.
Hold: The space in the hull that is used for the storage of cargo.
Hoist: The vertical edge of a sail: to haul aloft.
Hull: The main body of a boat or ship.
Impeller pump: A type of pump commonly used on large sailing vessels.
Inboard: Toward the center of a boat; sometimes used for “engine”.
In Irons: To head into the wind and refuse to fall of; a boat in irons will not go off.
Isobars: Bars or lines on meteorological maps to show pressure areas.
Jacklines: Ropes or wires that run along the side decks to allow the crew to attach harnesses for self-protection in case of foul weather.
Jettison: To throw overboard.
Jib: The triangular sail in front of the foremast, in front of the main sail.
Jib sheets: Lines that allow you to trim the jib.
Jibe: Changing direction/tack on a downwind course; to change from one tack to another by turning the stern through the wind; also spelled gybing.
Kedge Anchor: A secondary, lighter anchor.
Keel: The lowest part of a boat that stabilizes the hull and decreases sideways drift. In wooden vessels, frames are normally attached to the keel.
Knot: A measure of speed in navigation that is defined as one nautical mile per hour.
Latitude: The north-south distance of the equator measured in degrees.
Lazarette: The small space below deck, usually aft, where spare parts are kept or an outboard motor is mounted.
Lazyjacks: Lines or wires that are rigged from the mast to the boom to retain the sail when it is lowered.
Leech: Aft edge of a sail.
Leech line: The rope or wire that runs through the leech of the sail and controls its tightness.
Lee: The side facing away from the wind.
Lee helm: The leeward course an unsteered boat takes.
Leeward: The direction facing away from the wind. Pronounced like “loo-ard”.
Leeway: Sideways drift of a boat through wind or water current.
Lifelines: Line or wire that encircles the deck to prevent crew members from falling overboard, it attaches a safety harness to a fitting or jackstay.
Lines: Thin ropes used to control sails, secure spars and for manifold other important things aboard.
Log: A protocol of the actions on and course of the boat.
Longitude: The east-west distance from the meridian in Greenwich in degrees.
Lubber-line: Mark on a compass that indicates the forward direction of a boat.
Luff or luffing or to luff up: The forward edge of a sail; the verbs describe the action that brings the boat’s front closer to the wind; the flapping of a sail caused by the boat being head to wind.
Magnetic north: The direction to the magnetic north pole, which does not match with the geographic North Pole.
Magnetic variation: The variant angle of the difference between magnetic and geographic North Pole. The variation results from the movement of the magnetic North Pole.
Mainsail: The lowest sail on the mainmast.
Mainsheet: The line for controlling the main sails.
Mast: A vertical spar that holds the sails and their respective rigging.
Masthead: The top end of a mast.
Mayday: An internationally valid distress signal that is repeated three times and has highest priority of all signals.
Midship: Center of the vessel, middle between bow and stern.
Mooring: Action that secures a boat to a pier, anchorage or buoy.
Nautical Almanac: A calendar and advice book for nautical applications.
Nautical Mile: One minute of latitude, 1852 meters.
Navigation: The teaching of commanding a boat safely from one point to another.
Navigation Regulations: Also “Steering and sailing rules”; a set of rules that govern the movement of boats with respect to each other.
No-sail-zone: The area of plus minus 45 degrees into the wind in which boats generally can’t sail.
Oar: Long type of paddle used to row a boat.
Offshore wind: A wind blowing off the land.
Onshore wind: A wind blowing onto the land.
Outboard: Mounted externally to the boat, near the boat’s side – for example an engine.
Outhaul: Rope or wire that is used to haul out a sail.
Overboard: Outside the boat.
Painter: Mooring line attached to the bow of dinghies.
Pan Pan: The second-highest (after “Mayday”) priority signal that expresses distress.
Pier: A platform to which a boat can be moored.
Pile moorings: Moorings made from wood or metal piles driven into the ground.
Planing: A boat racing that fast, that hardly any part of the hull is under water; gliding.
Planing Hull: A hull built in a way to support gliding at high speeds.
Plotter: A nautical tool to plot a course on a map or grid of latitudes and longitudes.
Port: Left to the vessel as one faces forward; a harbor.
Privileged vessel: The vessel with the right-of-way according to nautical rules.
Pulpit: Metal railing or frame around the bow of a boat, mostly for safety reasons.
Pushpit: A pulpit around the stern of a boat.
Quarter: The portion of a vessel’s side near the stern.
Rake: The angle of a mast (forward/back).
Reaching: Holding a course with the wind roughly abeam.
Reef: An aid to reduce the size of a sail during periods of strong wind.
Rig: The sum of all sails, spars and masts on a boat.
Rigging: The sum of all ropes, lines and wires that hold and control sails and mast on a boat.
Roach: The curved part of a sail that goes beyond a straight line between head and clew.
Rocker: The curve from stern to keel to bow.
Rode: The line and chain that secure the anchor to the boat.
Rub-rail or strake: A rail used as a buffer to protect the hull when the vessel is moored to a pier or another boat
Rudder: Underwater board that supports the steering of a boat.
Run: Point of sail with the wind directly aft.
Running: Sailing on a direct downwind course.
Running rigging: The sum of all lines and wires that control sails and that can be manually adjusted whilst sailing.
Running Lights: Light signals that indicate the position of a vessel in the hours of darkness.
Safe course: A determined safe route across dangerous water.
Sail: A kind of cloth that is arranged in a way to catch wind and transmit its power via a mast and rigs into a sailing vessel.
Sailing Rig: Pretty much all gear on a boat that is of immediate use for sailing it except the boat itself – sails, booms and masts, lines and wires.
Safe room: All water surface within a certain distance from potential hazards such as the shore.
Schooner: A sailing boat or ship with at least two masts. Generally used for ships of larger size.
Sculling: A technique of “rowing” a dinghy with a single oar.
Scupper: Drains in the decks or inner parts of boats (cabins, cockpit and alike) that lead water overboard.
Sea Cock: A valve in the hull that protects the plumbing pipes of a yacht to water from outside the vessel.
Securite: A safety signal that precedes a warning.
Seaworthy: In principle, any boat meeting all necessary requirements for sailing offshore.
Secure: To fasten a rope, line or wire.
Sheets: Lines or wires that are applied to a sail in order to control and adjust it.
Sideways force: The part of the force generated by the wind in the sail that moves the boat sideways.
Skeg: A fitting to which the rudder is attached.
Slack: loose ropes, lines, wires.
Slip: A ramp for launching a boat.
Sloop: A boat with only one mast and sail.
Sole: The floor in a cabin.
Spar: A pole on a boat that is normally used to spread a sail or to support lines and wires.
Spinnaker: A light, triangular, balloon-like sail that is used in front of all other sails for sailing downwind.
Spreaders: Horizontal structures that branch off the mast towards the sides of a vessel to control the angle of the shrouds.
Spring line: A line used when the boat is docked to keep her from moving forward and aft.
Springtides: Tides with the maximum difference between highest and lowest water level.
Spritsail: An aft sail that is supported by a spar from the mast.
Standing Rigging: Opposite of running rigging, all rigging that remains fixed on the boat to support spars and mast.
Starboard: Right-hand side of a boat or ship as one faces forward.
Stay: A line or wire that supports the mast in a direct line from the mast to the bow of a boat.
Staysail: A sail that is set on a stay instead of a mast.
Stem: The upright structure at the bow.
Stern: The aft part of the boat.
Stern line: A mooring line that runs off the stern.
Stern quarters: The aft corners of the hull.
Tack: Forward lower corner of a sail; steering the bow of a vessel through the wind; to change course by passing into the wind.
Taffrail: Rail at the stern of a vessel.
Tail: To pull on the tail of a sheet when winching.
Tell-tales: Strips of some kind of fabric that are attached to sails to indicate the wind and right trim.
Tender: Small boat that is used to transport passengers to bigger vessels.
Tide: The rise and fall of the sea water level due to the moon’s gravity.
Tidal drift: Strength of the tidal drift.
Tidal stream: Current caused by the rise and fall of the tides.
Tiller: A control handle that is connected to the rudder with a universal link.
Topping lift: A line or wire that supports the boom when a vessel is moored.
Topsides: The part of the hull between the water surface and the edge of the deck.
Transom: The surface that makes the stern of a boat.
Traveler: A sliding fitting to which the mainsheet is attached, keeping the boom in the same place as it is moved in and out.
Trim: To adjust the sails; The position of the sails relative to the wind.
True north: The direction to the geographic North Pole.
True Wind: The wind that is felt by somebody stationary.
Upwind: Any course closer to the wind than a beam reach.
Veer: A change of direction, as in the wind.
Vessel: Any kind of boat, ship or yacht.
Warp: Anchor line or mooring line.
Waterline: An imaginary line around the hull at the surface of the water when the boat is on an even keel.
Winch: A mechanical device that is used to pull in/trim sheets. It consists basically of a coil, on which the line is wound, and a crank to do the winding.
Windward: Towards the wind, opposite of leeward.
Yacht: From the Dutch word “Jaghd”, widely used term for pleasure vessels, mostly bigger boats primarily for sailing, but often seaworthy and equipped with strong engines