Glossary of Boating Terminology
Abeam: At right angles to the centerline of the boat.
Aboard: On or in a boat.
Aft: Near the stern, towards the stern.
Amidships: In the middle of the boat.
Apparent Wind: Wind felt when moving. Combination of the true wind and wind created by motion through the air.
Astern: Behind the stern of a boat.
Backstay: Rigging that supports the mast from the back of the boat. Typically a wire rope or metal rod connected to the top of the mast and the stern of the boat.
Battens: Thin, rigid strips placed in a pocket in the leech of a sail to help shape the sail more efficiently. Typically made of wood, metal, or plastics.
Beam: The width of a boat at its widest point.
Beam Reach: The point of sail on which the boat sails perpendicular to the wind.
Bearing: The direction from one position or object to another.
Beat: To sail on a close-hauled point of sail.
Belay: To secure a line.
Ballast: Any weight used to increase the stability of a boat.
Block: A nautical name for a pulley.
Bolt Rope: Rope sewn into the side of a sail to give it strength and to facilitate attaching that side of the sail to the boat.
Boom: The horizontal spar or pole which attaches to the mast and extends aft. Used to control the shape and position of the mainsail.
Boom Vang: A block and tackle system, running from the boom to the bottom of the mast, which prevents the boom from lifting as the sail fills with wind.
Bow: Forward part of the boat.
Broad Reach: The point of sail where the wind crosses one of the back quarters of the boat.
Capsize: To turn a boat on its side or upside down to the point where it will not right itself.
Cast Off: To release or let go of a line.
Centerboard: A thin board which pivots down into the water. Provides minimal stability to the boat and prevents leeway.
Centerboard Trunk: A slot in the hull through which the centerboard pivots up and down.
Cleat: A device or fitting which secures and holds the tension on a line.
Clew: The lower, rear corner of triangular and quadrilateral sails. Or, the lower, “free” corners of a square sail.
Close-Hauled: The most windward point of sail. The closest angle to the wind in which a sailboat’s sails will remain full. Typically about 45° off of either side of the eye of the wind.
Close Reach: The second most windward point of sail. A windward course that is not as close to the wind as close-hauled.
Cringle: A hole through a sail or thin material through which lines can pass. Cringles are typically reinforced with a grommet.
Course: The direction or path a boat is taking.
Cunningham: A special type of downhaul which passes through a cringle slightly above the tack of a sail and secured to the mast. Applies downward force on the sail tensioning the luff.
Daggerboard: Similar to a centerboard in purpose and functionality. The difference being that a centerboard pivots up and down, whereas a daggerboard slides vertically up and down.
Downhaul: A line, or block and tackle system, attached to a spar or sail which applies downward force.
Eye of the Wind: The precise direction from which the wind is coming from.
Fairlead: A fitting or device used to change the direction of a line to provide a better angle to a sail, winch, block, or cleat. Typically found on sheets before the cleat.
Fall Off: To adjust course to leeward; turn away from the wind.
Fend Off: To push another vessel away, or hold a vessel off some object.
Foot: The bottom edge of a sail.
Fore: Towards the bow.
Foresail: Synonym of headsail. A sail forward of the mainsail. An example of a specific foresail would be a jib.
Forestay: Synonym of headstay. An item of rigging used to support the mast from the front. Typically a wire or metal rod attached somewhere along the forward side of the mast and to the bow of the boat.
Furl: To fold or roll up a sail.
Give Way: To allow another vessel right of way.
Gooseneck: A fitting connecting the boom to the mast.
Grommet: A ring placed around a hole through a thin material. Provides structural support around the hole, and prevents tearing or abrasions of the material. In boating, it is most commonly seen reinforcing a cringle.
Gudgeon: A circular fitting that allows for pivoting of a fixture attached to it. Most commonly used as a fitting on some boats for the rudder to attach via pintles.
Gybe: Alternative spelling of jibe that is older and less common. See jibe.
Halyard: A line used to raise and lower sails.
Head: The topmost corner of a sail.
Header: A shift in wind direction towards the bow of the boat.
Heading: Direction in which a vessel is pointing.
Headsail: Synonym of foresail. A sail forward of the mainsail. An example of a specific headsail would be a jib.
Headstay: Synonym of forestay. An item of rigging used to support the mast from the front. Typically a wire or metal rod attached somewhere along the forward side of the mast and to the bow of the boat.
Headway: Forward motion.
Heave: To lift or throw.
Heel: The leaning of a vessel to either side.
Helm: General description of the means of steering. Examples are a tiller or wheel.
Hike/Hiking Out: To sit on the side gunwale of a boat and lean out to counterbalance a boat’s heel.
Hitch: A method of attaching a line to another object such as a cleat, spar, or ring.
Hull: The main body of a boat.
In Irons: A name given to the situation where a sailboat is bow into the wind without enough momentum to turn out. In other words, the boat is stuck in the no-go zone.
Jib: A type of triangular headsail.
Jib Sheet: A sheet used to control the position of the jib.
Jibe: A turning maneuver in which the stern of the boat passes through the eye of the wind and the boat changes from one tack (boat orientation) to the other.
Jibstay: A not very common synonym of forestay and headstay.
Knot (in a line): A method of bending a line around itself to serve a function. Stopper knots, for example, are formations in a line that prevent the line from going through a fitting.
Knot (unit of speed): A common nautical unit of speed. 1 knot = 1 nautical mile per hour = 1.15 miles per hour.
Lee: A common shorthand word used in place of leeward. See leeward.
Leech: The back edge of a triangular or quadrilateral sail. The two vertical sides of a square sail.
Leeward: Nautical term meaning downwind or away from the wind.
Leeway: The leeward drift of a boat due to the force of the wind in the sails and against the hull.
Luff (side of sail): The forward edge of a triangular or quadrilateral sail.
Luff (maneuver): To alter course to windward until the boat is pointed bow into the wind.
Luff (sail reaction): The flapping of fluttering of a sail caused by the sail not being sheeted-in tight enough, or the bow being to far into the wind.
Mainsail: The largest sail on a modern sailboat. Set on the mast (or mainmast if the boat has more than one mast).
Mainsheet: A sheet used to control the position of the mainsail.
Make Fast: Secure.
Monohull: A vessel with a single hull.
Multihull: A vessel with more than one hull. Examples would be a catamaran and trimaran.
No-Go Zone: The area off either side of the eye of the wind in which a sailboat cannot sail. Approximately 90° wide on a modern sailboat.
Outhaul: A line used to pull the clew of the mainsail aft to adjust tension along the foot of the sail.
Painter: A short piece of line secured to the bow of a small boat to tie the boat to a dock or mooring. More commonly known as a bow line.
Pinch: To sail slightly inside the no-go zone causing the sails to just begin to luff.
Pintle: A pin or bolt on which another object pivots. In boating, pintles are used to attach some rudders to gudgeons on the stern of the boat.
Port: Left hand side of the boat when facing forward.
Quarter: The general direction off either side of a boat located approximately 45° off the stern.
Rudder: A thin board shaped object which hangs down into the water and controls a boat’s direction.
Run: The point of sail where the bow of the boat is furthest from the eye of the wind. The boat heads straight downwind.
Running Rigging: Lines, wires, and other objects used to set and adjust sail position and shape. Running rigging is usually frequently adjusted while sailing unlike standing rigging.
Sailing By the Lee: The situation where the wind is temporarily crossing the same side of the boat as the mainsail is set to. Severe risk of an accidental jibe.
Shackle: A device used to fasten or couple objects together. Commonly used to attach lines to other objects such as sails.
Sheet: A line used to control the in and out position of a sail.
Sheet In: To bring the sails in closer to the centerline of the boat by hauling in on the sheet(s).
Sheet Out: To ease the sails out, away from the centerline of the boat, by allowing slack into the sheet(s).
Shroud: Items of rigging used to support the mast along both sides. Typically wires or metal rods attached somewhere along the side of the mast and to the side of the boat.
Spreader: A rigid support that hold shrouds away from the mast, providing increased supporting power of the shrouds.
Standing Rigging: Lines, wires, and other objects used to keep the mast(s) upright and secure. Standing rigging is usually put in place, secured, and rarely, if ever adjusted.
Starboard: The right side of the boat when facing forward.
Stay: A wire or metal rod used to support the mast fore and aft.
Stern: The back end of a boat.
Stow: To put away securely.
Tack (corner of sail): The lower, forward corner of a triangular or quadrilateral sail.
Tack (boat orientation): Name given to a boat’s orientation relative to the wind. It is the side of the boat opposite the side the boom is set to. For example, if the boom is on the port side, the boat is on a starboard tack.
Tack (maneuver): A turning maneuver in which the bow of the boat passes through the eye of the wind, and the tack (boat orientation) changes from one side, to the other.
Tiller: A simple extension attached to the top of a rudder that protrudes into the boat facilitating rudder control.
Transom: The stern facing of the hull, or the aft most section of a boat if stern is open.
Traveler: Device for altering the angle that the mainsheet pulls on the mainsail/boom.
Trim: To adjust sails to get the best performance.
Turtling: When a capsized boat turns upside down so that the mast is submerged, pointing straight down.
Whisker Pole: A light spar attached to the forward side of the mast and the clew of the jib. Used to hold the jib in position while sailing downwind.
Windward: Nautical term meaning upwind or towards the wind.
Wing and Wing: Sailing the boat downwind on a run with sails set on opposite sides.
Wing on Wing: Less commonly used saying meaning the same as wing and wing.