A Glossary of Nautical Terms

by Sam Ivey

Altitude - In celestial navigation it refers to the angle of the sun or a star above the horizon. (See ELEVATION)

Back - When used in relation to wind, it refers to the wind shifting in a counterclockwise direction. (See VEER)

Backwind - To turn a sail so that the wind is caused to blow on the opposite side than would normally be the case.

Barkentine - A three to five-masted vessel, of which only the foremast is square-rigged.

Beam - The width of a vessel at the widest point. When preceded by PORT or STARBOARD, it designates the side of a vessel or that direction.

Beam Sea - A circumstance wherein the waves strike a vessel on either side.

Beat - To sail toward the wind with successive TACKS

Boom - A horizontal spar to which the foot, or lower edge, of a sail is attached.

Bowsprit - A spar running out from the bow of a boat, to which the FOREMAST stays are fastened and from which the JIBS are set.

Burgee - A colorful pennant, often used to identify a vessel as being from a particular yacht club.

Capsize - To overturn a boat or ship, or the act of so doing.

Club-Footed - A pattern of sail construction wherein the foot, or lower edge of a sail, is cut at an angle to raise the clew or rear corner.

Cutty Sark - A famous clipper ship of the 17th century, which earned its fame in the Australian trade.

Doldrums - Ocean regions near the Equator, characterized by calms or light winds; the calms characteristic of these areas.

Drogue - A contrivance attached to the end of a line and used to check the movement of a vessel.

Elevation - (See ALTITUDE)

Fix - A determined location in navigation, derived from established reference points.

Forecastle - (Fo’c’sle) The foremost portion of a ship. A short, raised deck at the bow of a ship.

Foresail - A sail flown from the foremast of a vessel.

Greenwich - A town in England, through which runs the Prime Meridian dividing the earth into two hemispheres. From this meridian all east-west navigational positions are determined.

Gunnel - A variant of GUNWALE. The upper edge of a boat’s side, reaching from bow to stern.

Gybe or Jibe - To maneuver a vessel sailing downwind so as to cause the stern to pass through the wind, bringing the wind from one side to the other.

Halyard - A line used to raise and lower a sail.

Headstay - The foremost support(s) of the foremast. (See STAY)

Headsail - (See JIB)

Helm - The tiller or wheel used to steer the vessel.

Heave-to - To position the sails of a vessel so as to cause them to counteract each other, thus inhibiting the vessel’s forward motion.

Hull-down - A circumstance that exists when the hull of a vessel seen at a distance appears below the horizon.

Irons - A term used to describe a vessel’s relationship to the wind that prevents its desired movement.

Jib - The foremost sail or sails of a sailing vessel.

Jetsam - Discarded cargo or solid trash jettisoned from vessels and found floating in the water or washed ashore.

Knot - A nautical linear measure, roughly equivalent to 1-1/8 statute miles. In ancient times, a knotted string with knots at intervals of 47 feet 3 inches.

Lateen - A triangular sail suspended from a yard at an angle of about 45 degrees to the mast. The term drives from the word “Latin,” implying “Mediterranean.”

Latitude - An imaginary line of demarcation, circling the earth horizontally, and measured in degrees north or south of the Equator.

Leeward - Pronounced looward. The side sheltered from the wind. A term used to indicate the direction of an object from a vessel. (See WINDWARD)

Limber Holes - Holes drilled horizontally in the vessel’s frames, permitting the passage of water.

Log - A propeller-actuated device for measuring the passage of a vessel through the water. A written record of such passage, inclusive of the relevant details.

Lugger - A swift and weatherly craft used for coastal trading and fishing, usually with two masts.

Longitude - An imaginary line of demarcation, circling the earth vertically, and measured in degrees from the Prime Meridian of zero degrees. (See GREENWICH)

Mainsail - The principal or largest sail on a vessel.

Marlinspike - A pointed tool used to separate strands of rope or wire so they may be spliced.

Meridian - A line of latitude or longitude encircling the earth.

Partner - A framework designed to strengthen the deck at a point where a mast or other device or structure passes through.

Off-the-wind - To sail with the wind aft of the vessel’s beam, that is, astern of the vessel’s athwartship midpoint.

Pintles - Vertical pins that serve to hinge the rudder to the vessel and allow it to swing left and right.

Port - The left side of a vessel when looking forward from the stern.

Preventer - A line used as an additional security to aid the standing rigging in strong winds. A restraint applied to a sail’s boom when sailing off the wind.

Quarter - The after part of a vessel’s hull between the beam and the stern.

Quarterdeck - That portion of a ship from which the Captain, Master or Officer of the Watch commands the sailing activities. Originally a smaller deck covering about one quarter of the vessel’s length.

Reach - To sail with the wind in any relationship to the vessel other than dead ahead or dead astern. As is close reach, beam reach or broad reach.

Reef - To reduce the area of a sail. That area of a sail so reduced.

Runabout - An archaic term for a small single-masted vessel, usually carrying a mainsail and a jib. What is modernly called a sloop.

Sandwich Islands - Those islands now known as the Hawaiian Islands. Discovered in 1778 by Captain James Cook, they were originally named after John Montagu, the 4th Earl of Sandwich.

Schooner - Originally a two-masted vessel carrying fore-and-aft-rigged sails. The foremast was the shorter of the two. Later, three or more masts were the pattern, with one or more square TOPSAILS added.

Sextant - An instrument comprised of mirrors and a graduated scale, used to measure the angle of the sun or a star above the horizon.

Sheet - A line or lines used to shift a sail from one side of a vessel to the other.

Shrouds - Part of a vessel’s standing rigging, used to provide lateral support for a mast.

Skiff - A small boat equipped with oars and used for a ship’s chores in harbor.

Spar - A general term for all poles in a vessel’s rigging.

Square-rigger - A multi-masted vessel fitted primarily with square sails.

Starboard - The right-hand side of a vessel when looking forward from the stern.

Stay - Part of the standing rigging that supports the masts fore and aft. Forestays run toward the bow; backstays run toward the stern.

Staysail - A triangular sail hoisted between the headsail(s) and the foremost mast. A sail hoisted between masts in the case of a large ship.

Strake - Each of a continuous line of planks running from bow to stern in the sides of a vessel.

Tack - To alter a vessel’s course by swinging the bow of a vessel through the wind. To proceed in a direction by tacking. The lower forward corner of a triangular sail. The lower windward corner of a square sail. Also the line attached to such corner.

Taffrail - The upper portion of a ship’s or, boat’s after-rail. The word is a variant of the Dutch word Taffereel denoting “carved panel.” Such ornamental carving was often the case on ancient 16th to 18th century ships.

Tiller - A handle attached to the rudderpost by which the vessel was steered. (See HELM)

Topsail - The second highest sail on a square-rigged ship.

Tradewinds - Winds that blow consistently in the same direction. They prevail in areas about thirty degrees above and below the Equator.

Trailboards - Wooden panels on both sides of the hull aft of the bowsprit. Decorative in design, they were often carved and were often seen to carry the vessel’s name.

Trim - To adjust the sails so as to utilize their maximum efficiency.

Trysail - A small sail, usually triangular in shape, hoisted in heavy weather in place of a larger sail.

Veer - The wind is said to veer when it moves in a clockwise direction.

Wear Ship - The opposite of TACK (See GYBE)

Weather - The direction from which the wind is blowing; to pass through or to clear successfully, as in to weather a headland, weather a storm.

Windward - (See WEATHER)

Yard - A long narrow wooden spar, slung from its center in front of a mast, and serving to support a sail attached to it.