Glossary of Nautical Terms

 

  • A - Code flag of the International Code of Signals with a signals with a single meaning, 'I have a diver down; keep well clear at slow speed'. It is a white and blue flag.
  • Aft - Towards, near or at the stern. Applied to wind it means wind blowing over the stern from 45 degrees to either side of it.
  • Aloft - Anything above the highest deck is said to be aloft.
  • Anemometer - An instrument for measuring wind speed.
  • Astern - Anything lying directly behind the vessel is said to be astern.
  • Avast - An order meaning to stop, hold fast.
  • B - Second flag of the International Code of Signals meaning, 'I am taking in or discharging, or carrying dangerous goods!' It is a plain red flag.
  • Bark - An alternative spelling to the word 'barque' which describes a three, four, or five masted sailing vessel fore and aft rigged on the after mast and square rigged on all others.
  • Barometer - An instrument for measuring atmospheric pressure.
  • Belay - To make fast a rope around a cleat, bollard or bitt.
  • Bow - The extreme forward end of the ship. The stem area. Also refers to the rounded part of a shackle.
  • C - Flag of the International Code of Signals meaning 'Yes'. It is of horizontal bands; blue, white, red, white and blue.
  • Cabin - Bedroom on a ship.
  • Capstan - A barrel that stands vertically with sockets around the top edge into which bars were fitted. Men walked these bars around, thus turning the capstan. The word 'capstan' can describe any winch drum.
  • Celestial - Pertaining to the sky or visible heavens.
  • Chart - The 'map' used by boatmen. It shows depths, lighthouse positions, and characteristics and all information relevant to safe navigation.
  • Clewline - Rope for hauling up the clew of an upper squaresail before furling, principle is exactly the same. A rope from the deck passes through a block under the yard, (close to the mast) and makes fast at the clew. When hauled on the clew lifts to the yard and thus prepares the sail for furling.
  • Compass - An instrument used to ascertain direction. There are two types. One, the magnetic compass, is based on the attraction of the earth's poles. Two, the gyrocompass, consists of an electrically driven gyroscope aligned with the earth's axis.
  • D - A flag of the International Code of Signals meaning 'Keep clear of me" I am maneuvering with difficulty'. It is colored yellow, blue, yellow, horizontal bands.
  • Deadeye - Rounded hardwood block, grooved around perimeter to take shroud-end and pierced with three holes to take lanyards. An old method of tightening rigging now usurped by rigging screws.
  • Deck - Floor; top deck (weather deck). 'tween decks is the space between floors. Emigrants on Euterpe lived 'tween decks on their voyage to New Zealand. The orlop deck is the lowest deck on the Star of India. This deck covers or overlaps the bilge area or hold.
  • Dog Watch - The two two-hour watches between 1600 hours and 2000 hours (4 p.m. and 8 p.m.) to effect a change in pattern of the otherwise regular watch times of four hours.
  • Dory - A small, flat-bottomed boat with high sides and great sheer of the gunwale. It usually was used as a fishing boat, whose design allows stacking of several boats on the decks of commercial fishing ships. They are transported to fishing "grounds" where they are put in the water, and rowed to the fishing areas.
  • Draft. The depth of water at which a vessel floats. It is the amount she 'draws.'
  • E - A flag of the International Code of Signals meaning 'I am altering my course to starboard'. It is colored blue (above) and red (below) in two horizontal bands.
  • Ebbtide - The receding tide.
  • Eddy - A current of water running contrary to the main, or host, stream.
  • Electrolysis - The destructive action of salt water combined with dissimilar metals. The salt water acts as an electrolyte carrying an electric current from one type of metal to another.
  • Euterpe - Former name of the Star of India.
  • Even Keel - Said of a vessel when her keel is horizontal and her draught is the same for and aft.
  • F - Flag of the International Code of Signals meaning, 'I am disabled, communicate with me.' A white flag with a red diamond in the center.
  • Fathom - Six feet or 1.8 meters.
  • Ferry - Any vessel used to carry passengers across a harbor or river on a regular basis.
  • Figure Head - The ornamental figure carved of timber and placed beneath the bowsprit.
  • Forward - Toward the bow (front) of the ship.
  • Freeboard. The distance between the water line and the deck.
  • Furling - The gathering in of a sail and lashing it down.
  • G - Flag of the International Code of Signals meaning 'I require a pilot'. When made by fishing vessels operating in close proximity it means, 'I am hauling nets'. It is colored alternating yellow and blue vertical stripes.
  • Gale - A strong wind. Under the Beaufort Wind Scale a gale is described as being a moderate gale (Force 7, 28 to 33 knots), a fresh gale (Force 8, 34, to 40 knots), a strong gale (Force 9, 41 to 47 knots) and a whole gale (Force 10, 48 to 55 knots).
  • Galley - The kitchen aboard a ship.
  • Gangplank - A portable 'bridge' between ship and wharfs to allow safe access.
  • Gunwale - The upper edge of the ship's side.
  • Gyro Compass - A gyroscope electrically driven and aligned with the earth's axes so that it indicates true north. The main unit is mounted well down below decks from where repeaters are fed. The gyro must be adjusted for latitude and ship's speed. Ineffective in latitudes higher than 75 degrees.
  • H - Flag of the International Code of Signals meaning 'I have a pilot aboard'. It is white and red in two vertical bars.
  • Hand - A crewmember so called because a man is considered as having only one useful working hand aboard ship. The other is 'for the ship' - to hang on with.
  • Hard Tack - Said of ship's biscuits and generally used to denote any below average food.
  • Hull - The body of a vessel.
  • Hurricane - Force 12 on the Beaufort Scale. 64 to 71 knots wind. More generally used to describe destructive winds in certain parts of the world well above those speeds.
  • I - Flag of the International Code of Signals. Means 'I am altering my course to port'. It is yellow with a black circle.
  • International Code - System of flag and Morse signals for communication between ships and ship and shore. Last revised in 1964.
  • Ironbound - A rugged coastline offering no landing for small boats.
  • J - Flag of the International Code of Signals meaning, 'I am on fire and have dangerous cargo on board: keep well clear of me'. It has three horizontal bars blue, white and blue.
  • Jacob's Ladder - A ladder used for climbing aboard or aloft.
  • Jetty - A pier or wharf for the use of shipping.
  • Jib Boom - The spar projecting forward from the bow to which all jib tacks are fastened.
  • K - Flag of the International Code of Signals meaning, 'I wish to communicate with you.' It has two vertical bands, yellow and blue.
  • Keel - The 'backbone' of any ship. It lies fore and aft along the centerline of the bottom.
  • Knot - Nautical unit of velocity used internationally regardless of national measurement system. It is 6,080 feel per hour. Because the knot is a complete statement, it is unnecessary and incorrect to state a speed as so many 'knots per hour'.
  • L - Flag of the International Code of Signals, means, 'You should stop your vessel instantly'. Colored yellow and black.
  • Lanyard - Short length of line used for securing objects.
  • Latitude - The distance from equator measured as an angle at the center of the earth from the equatorial plane.
  • Lazarette - A stowage area either right forward or right aft. Is often incorrectly used to denote stowage space aft only.
  • Leeward - The direction in which the wind blows.
  • Log - A ship's diary. Also, a device which is trailed from the stern of a boat and used to measure the speed of the boat.
  • Longitude - The position on earth of any place measured in degrees east or west of Greenwich.
  • M - Flag of the International Code of Signals meaning, 'My vessel is stopped and making no way through the water'. Blue with a white cross.
  • Mariner - A person employed aboard ship.
  • Meridian - Imaginaries line which passes north and south around the earth crossing the equator at right angles.
  • N - Flag of the International Code of Signals. Means 'No' (negative' or 'the significance of the previous group should read in the negative'). Color checkered blue and white.
  • Nautical Mile - One sea mile. 6080 feet which is 1/60 of a degree on the equator.
  • Navigation - The art of safely conducting a vessel from one place to another. There are two forms; coastal navigation and celestial navigation. The former requires only a knowledge of how to take compass bearings whilst the latter requires a knowledge of sextant work and the deduction of sight-readings.
  • O - Flag of the International Code of Signals meaning 'man overboard'. It is diagonally divided into two areas of red and yellow.
  • Ocean - Describes the expanse of water covering the globe. There are only five oceans; the Pacific, Atlantic, Indian, Arctic and Antarctic.
  • Ombrometer - Rain gauge.
  • Orlop Deck - The lowest deck in a battleship.
  • P - Flag of the International Code of Signals meaning: 'All persons should report aboard as the vessel is about to proceed to sea.' At sea, it may be used by fishing vessels to mean; 'my nets have come fast upon an obstruction.' Known as the 'Blue Peter'. Colored blue with white oblong in center.
  • Parallel ruler. Two rulers connected by steel or plastic beans which can be 'walked' across a chart to transfer a line from one area to another.
  • Pilot - A person of deep-sea qualifications employed by a local authority to take a ship into or out of port or along restricted coasts where the captain requires local knowledge.
  • Pilot Boat - The vessel used to carry the pilot from shore to ship. It operates from a 'pilot station.'
  • Pitching - The motion of a vessel when plunging into a headsea.
  • Port - When facing the bow, port is the left side of a ship. Also a harbor.
  • Ports - Small windows in the hull of a ship.
  • Purchase - The amount of 'leverage' gained in blocks and tackle. Stated as unit of advantage.
  • Q - Flag of the International Code of Signals meaning; 'My vessel is healthy and I request pratique'. Colored plain yellow.
  • Quadrant - Quarter of a circle. A navigational instrument now replaced by the sextant.
  • R - Flag of the International Code of Signals meaning; 'I have received your last signal'. A red background with a yellow cross.
  • Ratlines - Ropes lashed across the shrouds to provide a footing and handhold for crew going aloft.
  • Rig - To fit shrouds, stays, braces, and other gear to permanent parts of the ship. In addition, a 'rig' is the arrangement of masts and sails and other spars on a vessel.
  • Rudder - The device used for steering.
  • S - Flag of the International Code of Signals meaning; 'My engines are going astern.' White background with blue oblong center.
  • Sail - Any canvas or synthetic fabric spread to catch the wind and drive a vessel along.
  • Sailor - One who sails aboard any type of ship, be it power driven or sail.
  • Saloon - Traditionally the mess rooms for deck officers. Contemporarily, it is used by yachtsmen to describe the lounging area aboard a small boat. Usually is equipped with dining table and settee berths.
  • Sextant - A navigational instrument for measuring angles. Primarily used to measure the angle between a celestial body and the earth's horizon, but can also be used in coastal navigation for measuring vertical angles between the shoreline and the top of a lighthouse or tower or horizontally between headlands, etc.
  • Shrouds - Strong, non-running lines which support the masts laterally or athwart ship.
  • Spars - Pieces of lumber or metal used for masts, yards, booms and gaffs.
  • Starboard - The right-hand side of the vessel, looking forward.
  • Stays - Strong lines which support the masts in a fore and aft direction.
  • Stern - The rear of the boat.
  • T - Flag of the International Code of Signals meaning, 'Keep clear of me; I am engaged in pair trawling'. Colored red, white and blue in vertical stripes.
  • Tide - The rise and fall of the sea due to centrifugal force of the rotation of the earth and the gravitational pull of the sun and moon.
  • Tiller - A lever fitted directly into the rudder head and used as a steering device.
  • Trade Winds - A belt of constant winds around the earth's surface blowing from a high-pressure system into the equatorial low pressures and curved towards the west by the earth's rotation. Generally speaking, the winds blow southeast between 10 to 20 degrees latitude in the Southern Hemisphere and northeast between similar parallels in the Northern Hemisphere.
  • U - Flag of the International Code of Signals meaning, 'You are running into danger'. It is checkered white and red.
  • Unfurl - To free the sails preparatory to hoisting.
  • V. Flag of the International Code of Signals meaning, 'I require assistance'. A red diagonal cross on a white background.
  • Variation - The angle between true north and magnetic north caused by the natural magnetic movement of the earth's poles.
  • Vessel - An overall description for any and every type of boat, ship, yacht, launch, etc.
  • W - Flag of the International Code of Signals meaning, 'I require medical assistance'. Colored blue, white and red.
  • Wake - The distributed water behind a vessel under way.
  • Wearing Ship - Going from one tack to another by turning the ship's stern through the wind. Sometimes called 'doing an old man'.
  • Weather - The phenomena within the earth's atmosphere caused by ascending and descending currents over hot and cold regions respectively plus the rotation of the earth.
  • X - Flag of the International Code of Signals meaning, 'Stop carrying out your intentions and watch for my signals'. A white background with blue cross.
  • Y - Flag of the International Code of Signals meaning, 'I am dragging my anchor'. Yellow and red diagonal stripes.
  • Yard - Spar fitted athwartships from which hangs the squaresail.
  • Yawl - A two masted sailing boat with the mizzenmast aft of the rudder.
  • Z - Flag of the International Code of Signals meaning, 'I require a tug'. When made by fishing vessels operating in close proximity to fishing grounds it means, 'I am shooting nets'. Colored black, yellow, blue and red.
  • Zenith - Point in the heavens directly above the observer.

 

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