Maritime Dictionary – Everything that Starts with the Letter “L”

by | Last updated Nov 24, 2023 | Maritime Dictionary | 0 comments

L – Code flag; You should stop your vessel instantly. Morse Code; ● ▬ ● ●.

L flag + four numerals – Code flags; Latitude.

La Niña – See El Niño.

Label Clause – Inserted in policies of marine insurance covering bottled goods. Excludes claims for damaged or discoloured labels.

Labile – Term applied to atmosphere when lapse rate exceeds adiabatic lapse rate.

Labour – As applied to ship, when she is straining under the force of heavy weather.

Labrador Current – A cool North Atlantic current setting Southerly along the Eastern far North American coastline, associated with fog and icebergs.

Labyrinth Packing – Invented by Sir Charles Parsons. Escape of steam is throttled by successive glands, each having less clearance than the preceding gland.

Laced Mainsail – Mainsail that is laced to main boom. First used in British waters by ‘America’ in 1851

Lacing – Running line by which a sail is laced to a gaff or boom, or to another sail. 2. Line by which a boat’s canvas cover, or other canvas gear, is secured in place.

Lade – Old form of ‘Load’. 2. Deepest part of an estuary when caused by outflow of main stream.

Laden in Bulk – Said of a vessel carrying a bulk cargo in all holds.

Ladies’ Ladder – Name applied to ratlines of rigging when they are closely spaced.

Lading – That which is loaded into a ship. The act of loading.

Lady of the Gunroom – Originally, a night watchman in the gunroom. Later, a marine responsible for care and cleanliness of gunroom.

Lady’s Hole – Small compartment in which gunroom stores were kept.

Lag – Interval between cause and effect. Time taken by a registering instrument to adjust itself to a change in the value it is registering. A slowness in following up.

Lag Bolt – A screw with a hex or square head.

Lagan – Jettisoned goods that sink and are buoyed for subsequent recovery.

Lagging – Non-conducting coating of a boiler, cylinder, or other container in which transfer of heat must be prevented. 2. A falling behind; being late in occurrence or arrival. 3. Lagging of tide is an increase in the time interval between successive high waters. Roughly speaking, it occurs as tide increases from neap to springs.

Lagoon – Sheet of water connected with sea but nearly surrounded by land.

Lagoon Reef – Atoll surrounding a lagoon.

Laid Up in Ordinary – Said of a warship when paid off and under charge of master attendant of a dockyard.

Laid-up Tonnage – Vessels not in active service.

Laid-up – Not in service.

Lambda – Greek letter (λ). Used as a symbol to denote the directive force of a magnetic needle, in a given position, as a proportion of the directive force it would have if entirely free to respond to terrestrial magnetism alone.

Lame Duck – A disabled vessel being an easy target.

Laminar Flow – The smooth flow of a medium (water or air) initially slipping over the forward sections of a hull or wing (hydrofoil or aerofoil). In the after sections of the hull the medium typically breaks away as turbulent flow (eddies) creating drag.

Laminate – A structure built of successive layers, i.e.; glass fibre, plywood.

Lamp Trimmer – Rating responsible for the trimming and care of oil and candlelighting arrangements.

Lanby – Large Automated Navigation Buoy. Increasingly used in place of a lightvessel. A very large offshore light buoy.

Land Blink – Gloomy-yellow light over distant ice-covered land.

Land Breeze – Wind blowing seaward from land after sunset. Due to land temperature of atmosphere being below that of sea atmosphere. Sometimes applied to any off-shore wind. See sea breeze.

Land Waiter – Customs officer attending a vessel that is discharging a cargo liable to duty.

Land Wind – An offshore wind.

Landfall – Land first sighted when approaching from seaward.

Landfast Ice – Ice that is fast to the land.

Landing – Overlap of strakes or plating. A place suitable for a vessel to engage in disembarkation.

Landing Account – Statement of goods landed at dock or wharf, and of charges for warehousing and storing.

Landing Craft – Vessel built for the purpose of landing men or materials on a beach. Very shallow draft forward, with bow door, and with engines aft.

Landing Order – Document authorising transference of goods from ship to shore.

Landing Strake – Second line of planking below gunwale.

Landlubber – Seaman’s derogatory name for a landsman, or incompetent seaman.

Landmark – Shore object, sometimes especially erected, that assists seamen in identifying their position when in sight of it.

Lands – Overlaps in planking of a clincher-built boat.

Lane – Narrow waterway through ice.

Lane Metre – A 1.0 metre in length x 2.0 metre in width area of deck (linear metre) used in assessing capacity of Ro/Ro ships.

Lang’s Lay – In this type of lay of rope or wire the strands of the rope are laid in the same direction as the yarns in the strand.

Langrage – Former missile used for destroying rigging of enemy ships. Was a bundle of scrap iron, bolts, etc., and was fired from a gun.

Language Test – Examination of a seaman, engaged at a port within Home Trade limits, to ascertain that he has sufficient knowledge of English to understand all orders he may be given. Lantern. Casing, with transparent sides, in which a light is carried.

Lanyard – Rope or cord used for securing or attaching.

Lap – Overlap of edge of one plate along the edge of another. 2. The cutting off of steam supply to a piston before end of stroke.

Lap or Overlap – The distance that one component overlays another, typically with planking.

Lap Strake – Clinker planking, in which planks overlap at the edges, as distinguished from carvel (smooth).

Lapse Rate – Amount by which temperature of atmosphere alters with increase of height. Usually about 0.6°C per 100 metres. Is positive if decreasing with height, negative if increasing.

Lapstrake – Alternative name for ‘Clincher’ build of boats.

Larboard – Opposite to starboard. Formerly in general use, but supplanted by ‘Port’ to avoid possible confusion due to similarity in sound. Historic name for the port side of a vessel.

Larbowlines – Nickname for men in port (larboard) watch.

Larch – European softwood timber that bends and steams well with high marine durability, uses traditionally include clinker planking.

Large – Said of a vessel sailing with wind abaft the beam but not right aft.

Laridae – One of the gull families. Are swimmers with slender beaks, lateral nostrils, long wing span. Hind toe is a spur, and is not connected to outer toes. Plumage is usually white with a certain amount of grey.

Larinae – True gulls. Somewhat similar to Laridae, but beak is wider and stouter. Wings are long and pointed; feet are very powerful.

Lascar – Native of east India employed as a seaman.

Lascar Agreement – Special and approved form of agreement under which lascars are engaged, carried and discharged by ships.

Laser – Mini class of cat rigged sailing dinghy.

LASH (Lighter Aboard Ship) – A ship specially constructed to carry loaded lighters or barges. These are floated on board in one port and floated out at the discharging port ready to be towed away.

Lash – Secure with a line.

Lashing – Rope used for securing anything in place, or for binding two objects together.

Laskets – Beckets along edge of a bonnet or drabbler. Used for attaching these sails to the sail above.

Last Known Position (LKP) – witnessed, reported, or computed DR position of a distressed craft.

Lateen Rig – Sailing rig embodying a lateen sail.

Lateen Sail – Triangular sail with a vertical leech and inclined luff. Is laced to a yard and suspended at about mid-distance along yard.

Lateen Yard – Long yard to which luff of a lateen sail is laced.

Latent Heat – Amount of heat absorbed and retained by a substance, or body, when changing from a solid to a liquid; or from a liquid to a gas.

Lateral Resistance – Resistance to sideway movement set up by underwater body of a vessel.

Latitude – Angular distance from Equator. Measured by arc of meridian intercepted by Equator and parallel of latitude passing through a given point.

Launch – To move a vessel into water so that she becomes waterborne. 2. To move a longitudinal object in the direction of its length. 3. Large open or halfdecked boat, particularly a large diagonally-built rowing- and sailing-boat used in R. N.

Launching Ways – Large, rectangular timbers, or plating, down which slides the cradle supporting a newly-built vessel.

Law of the Sea – An IMO Convention to standardise International maritime law.

Laws of Oleron – Early shipping laws—about 13th century—brought into England by Richard I. They form the basis of most European laws regarding shipping.

Laws of Storms – Fundamental facts about the formation and phases of cyclonic storms.

Lay – The manner in which a rope is constructed; i.e.; right hand twist, left hand twist, hawser, shroud, plaited etc. The direction or position of; “to lay ahead”. 2. Tension put into rope when laying it up. See ‘Hard Laid’, ‘Soft Laid’.

Lay Aboard – To come alongside.

Lay Aloft – An order to crew to ascend the rigging.

Lay Days – Days allowed by charter party for loading and/or discharging cargo.

Lay In – Order given to men on foot ropes of a yard when they are to come in to the mast.

Lay Out – Order to men at mast to extend themselves at intervals along a yard. 2. To keep a vessel at a certain place until a specified time has elapsed.

Lay the Course – To keep a ship’s head on a required course.

Lay the Land – To cause the land to sink below horizon by sailing away from it.

Lay Up – To put torsion in yarns and strands so that they form rope or cordage. 2. To take a ship out of service and moor her in a dock or harbour.

Laying Hook – One of the hooks in a rope-making machine. End of strand is attached to it when laying up the rope.

Laying on Oars – Holding oars at right angles to fore and aft line of boat with blades horizontal and parallel to surface of water. Is used also as a sarcastic term for idling, or not pulling one’s weight.

Laying Out – Transcribing from plans or patterns the marks required for shaping a component.

Laying Up Returns – Return of part of premium paid when an insured vessel has been laid up for 30 (sometimes 15) consecutive days.

Laytime – Time allowed to load and/or discharge the cargo. It is expressed as a number of days or hours or as a number of tons per day.

Lazarette, Lazaretto – Storeroom containing provisions of a ship. 2. Ship or building in which persons in quarantine are segregated. The space above the afterpeak between decks.

Lazy Guy – Guy that consists of a single rope and is used for moving or temporarily securing, a boom or derrick when little weight is involved.

Lazy Painter – Additional painter that is of smaller size than proper painter. Used when mooring for a short time and no great strain is anticipated.

Leach – Leech of a sail.

Lead (Led) – Shaped mass of lead—weighing 10-14 Ib.—used with a marked line when ascertaining depth of water or nature of sea bottom.

Lead (Leed) – Direction in which a rope goes, or is guided, by blocks, sheaves, fairleads, cleats, etc. 2. Open-water channel between ice-sheets. 3. Arrangement of a slide valve so that some steam is admitted to exhaust side of piston a little before end of stroke. This cushions end of stroke, and ensures adequate steam for the commencement of return stroke. 4. Setting of crank of one engine a certain distance in advance of another.

Lead Ballast – Used in sailing yachts to keep centre of gravity as low as necessary. Previous to 1846, iron ballast was used. After 1876, the lead was put into the keel. Today in modern merchant ships, a water ballast system is used.

Lead Lights – Navigational lights placed in transit to mark an entry channel.

Lead Line – Special line used with hand lead. Usually about 30 fathoms of 1 1/8- inch untarred hemp. Marked with leather at 2 and 3 fathoms, white bunting at 5 and 15, red bunting at 7 and 17, blue bunting at 13, leather with circular hole at 10, two knots at 20 fathoms. If marked in metres: 1 & 11m—1 strip of leather; 2 & 12m—2 strips of leather; 3 & 13m—blue bunting; 4 & 14m— green and white bunting; 5 & 15m—white bunting; 6 & 16m—green bunting; 7 & 17m—red bunting; 8 & 18m— yellow bunting; 9 & 19m—red and white bunting; 10m—leather with a hole in it; 20m—leather with a hole in it and 2 strips of leather; See ‘Deep Sea Lead Line’.

Lead Mine – Nickname given to ‘plank on edge’ type of yacht, on account of the heavy lead keel necessary for stability.

Leading Block – Block used for altering the direction of a rope led through it.

Leading Edge – The forward edge of an object. A sail’s leading edge is its luff.

Leading Lights – Two or more lights that identify a leading line when they are in transit.

Leading Line – Line passing through two or more clearly-defined charted objects, and along which a vessel can approach safely.

Leading Marks – Objects that identify a leading line when in transit.

Leading Part – That part of a tackle fall passing through the blocks. It is, therefore, all the rope that passes between the blocks except that part that is the standing part at the time.

Leading Wind – Any wind that is abaft the beam.

Leads In Line – Navigational marks placed in transit that mark a charted feature.

Leadsman – Seaman engaged in taking soundings with hand lead and line.

League – Measure of distance three miles in length. One-twentieth of a degree of latitude. Old English measure of three sea miles of 6,000 feet.

Leak Stopper – Device for stopping a small leak, particularly when due to loss of a rivet, by passing the stopper through the hole and clamping it to ship’s plating by nut or screw. End passed outboard has a hinged bar that drops athwart hole, when passed through, so anchoring outboard end on ship’s plating.

Leakage – That which has escaped by leaking. 2. Allowance made for loss due to leaking of contents of casks, barrels, etc.

Learners Guides – See workbooks.

Leathers – Pieces of leather that are stitched and/or tacked around an oar to protect it where it rides in the oar lock. They usually have a stop or “button” to keep the oar from sliding out of the oar lock when left unattended. The button can be a thin strip of leather or knotted twine that is tacked and/or glued in place on top of the leather at the handle end of the oar.

Ledge – Ridge of rock, or shelf-like projection of rock, below water. 2. Additional support, for decks, that goes athwartships between beams. Small timber chocks fitted under the deck that space the beams.

Lee – Area sheltered from the wind. Pertaining to that quarter towards which the wind is blowing.

Lee Board – Vertical wooden board, pivoted in forward edge, attached to side of flat-bottomed sailing craft and lowered into water to reduce leeway.

Lee Bowing – Yacht racing manoeuvre when on a wind. Giving way yacht goes about on lee bow of another, thus giving a back wind to the other.

Lee Gauge – Position to leeward, as relative to another vessel.

Lee Helm – Tiller to leeward to keep vessel’s head up to wind.

Lee Helmsman – Assistant helmsman, when required, in a sailing ship: the proper helmsman being at weather side of wheel. ‘

Related Article: How to Steer a Ship and Become a Better Helmsman

Lee Lurch – Heavy roll to leeward with a beam wind.

Lee Shore – Shore that is to leeward of a vessel.

Lee Side – The side opposite to that which the wind is blowing upon.

Lee Tide – Tidal flow that goes in same direction as prevailing wind.

Leech – Side edge of a square sail, after edge of a fore and aft sail.

Leech Rope – Boltrope on side of a square sail.

Leech-line – Halliard passing downwards from block at yard arm to leech of a square sail. Used for lifting sail when reefing or furling it.

Lee-ho’ –  A warning that the helm has been put down and that the vessel is coming up into the wind in order to go about.

Leeward – The area on the lee side of an observer, or named object.

Leeway – Distance a vessel is forced to leeward of her course by action of wind. 2. Angle between ship’s projected course and her track through the water.

Left-Handed – Said of ropes in which the strands trend to the left as they go away from an observer.

Leg – One part of a rope that is seized on the bight. 2. One tack when beating to windward under sail.

Leg of Mutton Sail – Triangular mainsail used in boats and yachts.

Legal Day – For payment of seamen, begins and ends at 00 hours.

Legal Wharf – Wharf legalised by Act of Parliament, or approved by commission from Court of Exchequer.

Legs – Strong pieces of timber placed vertically at the sides of a vessel to keep her upright when she takes the ground on a falling tide.

Lembus – Light, fast war vessel of the Romans.

Lend a Hand – To assist.

Length – Fore and aft dimension of a ship. Length between perpendiculars is measured from fore side of stem to after side of sternpost on summer load water line.

Length Between Perpendiculars (LBP) – The length between both the fore and aft perpendiculars, measured along the Summer Load Line.

Length between perpendiculars (LPP) – This is the horizontal distance between the forward and after perpendiculars.

Length of Wave – Usually measured as the distance between two successive crests, which is also the distance between lowest point of two successive troughs. Expressed in feet.

Length on the designed load water line (LWL) – The length, as measured on the water-line of the ship when floating in still water in the loaded, or designed, condition.

Length on the Water Line – the designed waterline for the vessel at her loaded displacement, more accurately termed the load water line or summer load line. The later is marked with the loadline marks (plimsoll line) to ensure compliant loading for the intended sea area of the passage.

Length overall (LOA): This is the length measured from the extreme point forward to the extreme point aft.

Lenticular – Cloud form in which upper and lower edges are convex, thus resembling a lens, or a lentil seed.

Leo (Lat. =Lion) – Constellation situated between R. A. s 09 h 20 m and 11h 50m; Dec. 0° to 38°N. Has several bright stars: Regulus, or Cor Leonis, Denebola, Algeiba, Zosma. 2. Fifth sign of Zodiac, extending from 120° to 150° celestial longitude. Sun is in this sign from July 22 to August 23, about.

Leonid Meteors – Meteoric shower visible in Leo about middle of November. Due to break up of a comet.

Less than Container Load (LCL) that is inefficient to fill a shipping container. It is grouped with other consignments for the same destination at a container freight station.

Let Draw – Order given when it is required that weather fore sheet of head sail of a craft tacking shall be released, so that sail can be controlled by lee sheet.

Let Fall – Order given when a square sail, that has been loosed, is to be dropped so that it can be sheeted home.

Let Fly – Order to release sheets fully. Given as a salute, or in a heavy gust of wind, or other emergency.

Let Go – Of an anchor. To let it drop in the water.

Related Article: Safe Anchoring Techniques – How to Drop the Ship’s Anchor and Not Lose Them

Letter of Credit – Document, addressed to certain bankers, or firms, and authorising them to allow stated persons or person to draw money, up to a specified amount, against the credit of the bank or firm issuing the letter.

Letter of Hypothecation – Written authority given to a lender of money and empowering him to sell goods, purchased with money advanced by him, if the undertaking to repay him be not fulfilled.

Letter of Indemnity – Document given by one person to another whereby the person issuing the letter renounces any claim he may have in specified circumstances.

Letters of Marque and Countermarque – Written authority, from a sovereign state, to attack enemy ships in retaliation for a loss suffered, and to resist attack from enemy ships.

Letters of Mart and Countermart – ‘Letters of Marque and Countermarque.’

Levanter – Easterly wind in Straits of Gibraltar during March, and from July to October.

Leveche – Hot S’ly wind on SE coast of Spain. Precedes a depression and is often accompanied by dust.

Levee – A large river embankment.

Level Lines – Lines representing boundaries of horizontal sections of a ship made by planes parallel to keel.

Leviathan – Biblical name for a marine monster. Name has been given to the Egyptian crocodile, to a large Mediterranean cetacean, and to a sea serpent.

Libeccio – South westerly wind – one of the eight traditional traders winds of the Mediterranean Sea – persistent in Northern Corsica.

Liberation – A slight nodding of Moon’s axis, together with a slight variation in her revolution, which result in her showing a little more than the area we see normally; 41 per cent being visible at all times, 59 per cent being visible at one time or another.

Liberation in Latitude – Due to Moon’s axis being inclined to Equinoctial her north pole is inclined towards Earth at one point in her orbit, and away from it at the opposite orbital point.

Liberation in Longitude – Moon shows one hemisphere only towards Earth, but as her speed in orbit is not uniform she shows a little of the other hemisphere when her angular velocity around Earth is greater or less than her rotational speed.

Liberty Man – R. N. seaman when on leave.

Liberty Ship – Standard cargo ship built in U. S. A. during World War II.

Liberty to Call – Inserted in charter party, or other document, when a vessel has permission to call at intermediate port or ports in circumstances specified.

Liberty – Shore leave.

Libonotos – See classical winds.

Libra – (Lat. = Balances, Scales.) Constellation between R. A. s 14 h 55 m and 15 h 45 m; Dec. 9°S to 25°S. Has two bright stars: Kiffa Australis and Zubenelg. 2. Sixth sign of Zodiac, extending from 180° to 210° celestial longitude. Sun is in this sign from September 23 till October 23.

Liburnian – Roman warship with a ram of 1st century. Name derived from the Liburnians of Dalmatia.

Licensed Pilot – Pilot duly licensed by the pilotage authority of a port or district.

Lie – To remain in a particular place or position.

Lie Along – To heel over because of wind.

Lie Along the Land – To sail parallel to the coast.

Lie By – To remain nearly alongside another vessel.

Lie Over – To heel over.

Lie To – To stop a ship and lie with wind nearly ahead.

Lien – Legal right to retain possession of another person’s goods until certain claims have been satisfied.

Liferaft – An inflatable survival device.

Lifebelt – See ‘L’.

Lifeboat Certificate – Issue by Board of Trade to a seaman who has passed an examination proving his competence to man and handle a lifeboat of a seagoing ship.

‘Lifeboat Service’ – Saving or attempted saving, of vessels, or of life and property, on board vessels wrecked, aground, sunk or in danger of being wrecked, sunk, or grounded.

Lifeboatman – One who mans a shore-based lifeboat. 2. ‘Certificated Lifeboatman’, or seaman holding a C. P. S. C.

Lifeboats – Boats compulsorily carried in a ship for preservation of crew and passengers in the event of foundering or wreck. 2. Specially designed, self-righting, and unsinkable boat that is maintained on coasts of maritime nations for rescue of persons from vessels wrecked in its vicinity. 

Related Article: Types of Lifeboats and Their Launching Mechanisms

Lifebuoy – Specially designed portable float for throwing overboard to sustain a person in the water until he can be taken into a boat or ship. Standard requirements are contained in SOLAS Chapter III 31.

Lifejacket – A buoyant life preserver that is worn. Personal floatation devices are graded PFD 1, (required for commercial vessels), PFD 2 and PFD 3.

Lifelights – See buoyant lights.

Lifeline – Rope rigged or attached for purposes of security or rescue. 2. Line attached to a man working overside, and attended by a man inboard. 3. Rope from head of davit to a boat in the water and alongside, for security of men in boat during hoisting and lowering. 4. Line stretched horizontally between mast and lift of yard when manning yards. 5. Line stretched along deck in heavy weather. 6. Line attached to a buoy floated down to a man in the water.

Life-Saving Appliances – All boats, rafts, buoys, jackets, line-throwing apparatus, and other appliances and stores carried for life-saving purposes.

Life-Saving Rocket – Pyrotechnic missile fired from shore to pass over a stranded vessel and carry a line for establishing communication between ship and shore.

Lift a Template – To construct a template based on measures taken from an existing ship’s structure.

Lift Strakes – Spray rails. Longitudinal members running fore and aft on the outside bottom of the hull. The purpose is to stabilize and create lift on a deep vee hull when under power.

Lift: A change in wind direction enabling a yacht to point in a direction that was previously too close hauled. A rope or tackle from a boom to the mast to support and move it for cargo working.

Lifting Gear – Derrick and cranes, with all their furniture and attachments, used when lifting and lowering weights.

Lifting Screws – Screw propellers that were formerly carried in ships carrying sails and engines. When under sail alone, propeller was lifted, by tackles, into aBanjo Framebuilt recess in counter—the tail end shaft being withdrawn. See ‘Banjo Frame’.

Lifts – Ropes from mast to arms of a yard, and used for supporting, canting, and squaring the yard.

Ligan – ‘Lagan.’

Light – Opening in deck or sides of a vessel for admitting light. 2. Established navigational beacon light. 3. State of a vessel when without cargo, or when not submerged to her load line. 4. To assist in carrying a fall or rope in a desired direction. ‘Light to!’

Light Airs – Intermittent wind that does not exceed three knots.

Light Along – To lift or carry a rope in the direction that it lies.

Light Bill – Receipt for light dues paid.

Light Breeze – Wind with velocity between four and six knots. Force 2 Beaufort Scale.

Light Draught – State of a vessel when her submerged volume is least. Technically, her draught when she has no cargo but her bunkers are full, stores complete, and boilers filled to working level.

Light Dues – Money chargeable on a vessel as part payment of cost of maintaining lighthouses, light vessels, and similar navigational aids.

Light Port – Scuttle or porthole fitted with glass.

Light Sector – That part of a circle in which a certain phase of a navigational beacon light is observable.

Light Ship – Cargo vessel when not carrying cargo.

Light Year – One of the units of astronomical distance. Distance that light travels in one year. Value is 5, 878, 310, 400, 000 miles.

Lightening Hole – Opening in a member, or fitting, when arising from removal of unnecessary material to reduce weight.

Lightening – To remove weight.

Lighter – Craft of barge type and without means of propulsion. Used for transport of goods to and from ships. Formerly used for taking goods out of a vessel to lighten her, and so allow her to cross a bar.

Lighterage – Loading or unloading of a lighter. 2. Carriage of goods in a lighter. 3. Charge made for loading or unloading into a lighter.

Light-Handed – When applied to crew, means ‘Short-handed’.

Lightning – Brilliant and momentary light due to discharge of atmospheric electricity from cloud to earth, or from cloud to cloud.

Lightning Conductor – Protective strip of copper, led from masthead to sea, for carrying away atmospheric electrical discharges. Essential in wooden vessels and in vessels with wooden topmasts.

Lights – A general term for the night illuminations of vessels/navigational aids whose specification is found in collision regulations, lists of lights and port information. A thick plate of glass fitted in a vessel’s structure to provide a watertight light ingress.

Lightship – Vessel, moored in a particular position and exhibiting a light and daymark to mark a navigational danger and to be a navigational aid.

Lightship Displacement – The extreme displacement of the ship when fully equipped and ready to proceed to sea, but with no crew, passengers, stores, fuel, water, or cargo on board. The boilers are filled with water to their working level and lube oil is to levels.

Lightvessel – See ‘Lightship’.

Lignum Vitae – Very dense oily African hardwood used for propeller shaft bearings.

Ligsam – Old “name for ‘Lagan’.

Limb – Edge of disc of a heavenly body, particularly Sun or Moon. 2. Graduated arc of sextant or quadrant.

Limber Boards – Removable boards forming covers of limbers.

Limber Chain – Long length of chain rove through limber holes for clearing them.

Limber Holes – Holes in floor timbers, or tank side-brackets, through which bilge water flows to pump suction.

Limber Rope – Rope rove through limber holes for clearing them.

Limber Strake – Strake next to keelson in a wood-built ship.

Limbers or Limber Holes  Channel formed by tank side-plating and skin of ship, into which any water in hold will run. In wooden ships, was a channel alongside keelson on either side: floor timbers being pierced on either side.

Lime Juice – Antiscorbutic carried in British ships and issued when on salt provisions, or risk of scurvy exists.

Lime Juicer – Nickname given to British ships by U. S. seamen, when British law first required lime juice should be carried and issued. Was used by British seamen as a nickname for a foreign-going vessel.

Limitation Clause – Sometimes inserted in a bill of lading to fix an upper limit to amount claimable for loss of an item of cargo.

Limitation of Liability – The limiting of the amount that can be claimed from a shipowner for loss of goods and/or life when due to a casualty to ship that was not due to fault or privity of shipowner. The amount in S. D. R.’s is the subject of the 1976 Convention.

Line – A light rope or hawser. Small rope used for a specific purpose. 2. Equator. 3. Number of ships in such formation that a straight line passes through them. 4. Delineation of ship form in a vertical or horizontal direction.

Line Fisher – Fishing vessel using line or lines.

Line Haul – The movement of freight over a trade route from one port to another.

Line of Battle Ship – Name formerly given to a heavily-armed warship fit to take a place in a line of battle.

Line of Bearing – Straight line through a ship or drawn on a chart, passing through positions at which an observed object would have the same bearing, either by compass or relatively.

Line of Position – Position line.

Line of Soundings – Series of soundings, with course and distances sailed between them, laid off to scale of chart in an endeavour to ascertain ship’s position. 2. Series of soundings made along a line, and at stated intervals, when surveying.

Line Squall – Squall that the observer sees as a rapidly advancing line. Usually short lived.

Liner – Vessel sailing regularly between specified ports. 2. Former name for a line of battle ship. 3. A line fishing vessel. 4. Packing piece placed between parts to adjust them. 5. Thin metallic sleeve in a cylinder, which is renewed when worn.

Lines plan – Ship’s plan drawings of waterlines, buttock lines and section lines shown in profile, plan and body (end) views. An additional offset table is often included to enable scaling up for taking off full size templates in the process of lofting.

Line-Throwing Appliances – Guns, rockets, and lines used by ships to establish communication when necessary. Lines are usually 120 fathoms in length; rocket can carry line 200 yards in calm weather.

Link Block – Metal block at end of slide-valve spindle. Carries slippers in which radius link moves when reversing engine.

Link Motion – Valve gear for reversing a reciprocating engine, and for regulating cut off of steam to cylinder. Consists of two rods, radial link, and two eccentric sheaves. Invented by George Stephenson.

Link Worming – Worming of hemp cables with small chain, to reduce chafe.

Linkage – A connecting mechanism.

Linking Up – Movement of link reversing gear so that slide-valve cuts off earlier than normal.

Lipper – Small sea that rises just above bows or gunwale.

Lips – See classical winds.

Liquid Compass – Magnetic compass mounted in a bowl filled with a liquid having a very low freezing point. Weight on pivot is reduced, and card is steadier in lively vessels when in a seaway.

Liquid Fuel – ‘Oil Fuel.’

LiquefiedPetroleum Gas (LPG) – is an alternative fuel to diesel or petrol.

List – Transverse inclination of a vessel.

Listing – The operation by which a vessel is inclined transversely. 2. Inclining transversely.

Little One Bell – R. N. name for one stroke on ship’s bell after changing a night watch. Is a signal for the watch to muster and be checked.

Littoral – Sea area between a coast and the 100-fathom line. Regions lying alongside the coast.

Liverpool Hook – Hook, in end of cargo runner, having bill of hook curved inward, and a downward inclined projection above the bill. Inward curving prevents accidental unhooking; inclined projection prevents hook lifting underside of beam.

Liverpool Pantiles – Nickname for ships’ biscuit.

Lizard – Rope or wire pendant with a round thimble at unattached end. Used as a fairleader, or for the attachment of a boat’s painter.

Lloyd’s – An international insurance market and world centre for shipping intelligence which originated in the 17th-century coffee house of Edward.

Lloyd’s Agents –. Representatives whose duties are to protect underwriters from fraud, negligence, needless expense, or mismanagement in the treatment of insured property that is in peril. They have a wealth of local and technical knowledge which they place at a Master’s disposal; but they do not interfere with the Master, or relieve him of his responsibilities.

Lloyd’s Bond – Stereotyped form of Average Bond approved and issued by Lloyds.

‘Lloyd’s List’ – Daily paper reporting movements of ships, rates of exchange, and other information of value to those interested in shipping matters.

Lloyd’s Numerals – Numerical code by which appropriate scantlings of a proposed vessel can be derived from intended dimensions.

Lloyd’s Policy – First printed 1779, and has remained the standard form since that date. All marine policies are based upon it.

Lloyd’s Register of Shipping – The oldest and largest ship classification society, established in 1760. An independent authority which publishes technical rules for the construction and maintenance of ships. Employs 1300 exclusive surveyors stationed all round the world and classifies nearly 40 per cent of the world’s merchant tonnage. Authorised to assign freeboards on behalf of some 50 governments and also carries out other statutory surveys in accordance with the International Convention for the Safety of Life at Sea. The Register Book, published annually with monthly supplements, describes every known merchant ship in the world of 100 tons gross and above.

Lloyd’s Signal Stations – Established and maintained all over the world for transmitting and receiving maritime information in one universal code. Almost entirely superseded by V. H. F. and other modern methods of communication.

Load – To put cargo into a vessel. 2.’Load’ of timber is a measurement of 50 cu. ft. of undressed wood, 40 cu. ft. of dressed wood.

Load Displacemen – The total weight of the vessel when floating at the designed summer draft.

Load Draught – Vertical distance from lowest part of keel to load water line.

Load Line Marks – Marks on a ship’s side showing the allowable freeboard for specified ocean area and season of the year.

Load Line – A hull marking indicating the maximum depth to which a vessel can be loaded also called the Plimsoll mark.

Load Lines – Marks cut into ship’s side plating and painted. They indicate maximum draughts to which vessel may be loaded in specified circumstances.

Load Star – Star used as a guide when steering. 2. Pole Star.

Load Stone – Magnetic oxide of iron, which is a natural magnet.

Load Waterline – Waterline when down to her marks.

Loading – Transfering cargoes from the shore terminal to the vessel’s hold or tanks.

Loading Port Survey – Inspection of a ship, particularly one loading refrigerated cargo of meat, before loading.

Lobe – The area of a radiation pattern of a radar pulse, between full power and half power points.

Lobscouse – Nautical stew made with preserved meat and vegetables. Particularly in Liverpool ships. Hence “Scouse” a man from Liverpool.

Lobster – A marine crustacean with pincer-like claws. Historical slang for red coated Imperial soldiers.

Local Attraction Former name for deviation of compass. Now confined to deviation due to magnetic attraction outside ship.

Local Hour Angle – The angle between the chosen position and the geographic position. Measured from the CP to GP in a westward direction.

Local Time – Time kept in a particular port or country.

Local User Terminal (LUT) – earth receiving station that receives beacon signals relayed by Cospas-Sarsat satellites, processes them to determine the location of the beacons, and forwards the signals.

Loch – Scottish sea lake. A gated water enclosure enabling vessels to pass up or down a canal that has several levels of water containment.

Lock – Artificial enclosure of water in which a vessel can be floated from one level to another.

Lock Gates – Pair of massive hinged doors at each end of a lock.

Locker – Chest, box, cupboard or compartment in which gear may be stowed. Can usually be locked, but chain locker is one exception.

Lockerman – A steward in charge of (silver, cruet, fruit) lockers.

Locking Bars – Iron strips lying athwart a covered hatch. Can be padlocked to coamings when required.

Locking Pintle – One of pintles of a hinged rudder. Has a collar on protruding lower end, to prevent accidental unshipment of rudder.

Locust Wood – Quality American hardwood timber with high marine durability, treenails.

Lode Star – ‘Load Star.’

Lode Stone – ‘Load Stone.’

Lodging Knee – Knee fastened in horizontal plane with its head, or platform, secured to side of beam.

Loft Template Method – System of shipbuilding in which certain parts of shell plating are marked off and punched from data obtained from scrieve board body plan.

Lofting – Lofting is the process of drawing the hull lines full size from the designer’s scale drawings. The intersections of the contours of various horizontal and vertical sections are measured from an imaginary “base line” using an architect’s scale. These junctions are then laid out, point by point, in their full size. Because it is difficult to take accurate dimensions from a small drawing, it is necessary to adjust these lines to assure that they are “fair”. A listing of these points is called a table of offsets. It takes a lot of space to loft.

Log – Instrument or apparatus for ascertaining ship’s speed through water and/or distance run. 2. Log book. 3. Abbreviation for ‘Logarithm’.

Log Board – Hinged pair of boards on which log readings, alterations of course, and other happenings, were entered in chalk during the watch. Superseded by ‘Deck’, ‘Scrap’, or ‘Rough’ Log.

Log Book – Book in which events connected with the ship are entered. Several may be kept, the principal being Official Log, Deck Log, Mate’s Log, Engineroom Log, Wireless Log.

Log Chip – Segmental piece of wood, ballasted along curved edge, attached to log line to keep it stretched when measuring ship’s speed through water.

Log Error – Difference between indication of a mechanical log and the actual distance travelled through the water. Always expressed as a percentage of the log indication.

Log Glass – Sand glass measuring interval of about half or quarter minute; 14 seconds and 28 seconds being common. Used for timing the line run out when heaving the log.

Log Line – Line attached to a log when streamed. Line used with towed log is non-kinkable and braided. Line used with ship log is small and specially made so that it will not stretch unduly.

Log Line Splice – Splice put in olden log line. End of one part was spliced some little distance along other part; end of other part being laid around first part and then spliced. Sometimes called a ‘Water Splice’.

Log Oil – Specially-prepared oil for lubricating mechanical logs.

Log Reel – Reel having extensions to the axle on which it turns, these extensions being used as handles when streaming the log.

Log Ship – ‘Log Chip.’

Log Slate – Slate used for same purpose as ‘Log Board’. London Conference Rules of Affreightment, 1893. Six rules that could be inserted in contracts of affreightment to clarify shipowner’s responsibilities and immunities.

Logarithm – Exponent of the power to which a fixed number called the ‘base’, must be raised to produce a given number. Base of common logarithm is 10. Fractional part of the exponent is termed ‘mantissa’.

Loggerhead – Bollard, in a whale boat, for snubbing harpoon line. 2. Spherical piece of iron on long handle. Heated and used for melting pitch.

Logging – Entering in a log book. 2. Punishment entailing the entry of man’s name, offence and punishment in the official log book.

Loll – Neutral equilibrium of an overloaded vessel whose centre of gravity is at or near its metacentre.

Lo-lo – Lift on-lift-off ship where cargo is handled by cranes.

Long Gasket – Length of small rope used at sea for securing a sail to yard when furled.

Long Glass – Sand glass used with ship log for speeds up to five knots. Runs down in 28 or 30 seconds. 2. A telescope.

Long Jaw – Said of a rope when the cantlines of strands lie at an angle that is appreciably less than 45° from the run of the rope.

Long Period Species – Tidal species that occur at intervals greatly exceeding a tidal day. The most common are those with 14 days and 19-year periods.

Long Period Variable – Star whose magnitude varies during a period between 50 days and two years or more. Majority have a period of about 300 days. Mira, in constellation Cetus, varies between magnitudes 3.5 and 9.0 in 350 days.

Long Ship – A historic Viking oared, sailing ship.

Long Splice – Splice that joins two ropes and can reeve through a block. Strand of each rope displaces a strand in the other, for a distance equal to about six times size of rope; end is then tucked. Remaining strand of each rope is half knotted to opposite strand.

Long Stay – Said of a cable of anchored vessel when amount of cable out is more than four times depth of water.

Long Tackle Block – Two sheaves, one above the other, in a long shell. Diameter of upper sheave is one-and-a-half times that of lower sheave. Used with a single block to form a purchase.

Long Timber – Single timber rising from cant timbers to top of second futtock.

Long Ton – 2,240 pounds in weight. Metric tons (2,250 lbs).

Long Waisted – Said of a vessel having a long waist between poop and topgallant forecastle.

Longboat – Formerly, longest and largest boat carried by a merchant ship. Length between 32 and 40 ft., beam 8 to 10 ft., carvel-built and flat floored.

Longitude – Intercepted arc of Equator, or angle at Pole, between the prime meridian and the meridian passing through a named position.

Longitudinal – Pertaining to length. Applied to any fore and aft member of a ship’s structure.

Longitudinal Bulkhead – Bulkhead going fore and aft in a vessel.

Longitudinal Centre of Buoyancy (LCB) – The point, on the fore and aft line of a vessel at which the upward force of buoyancy acts. It is measured from amidships either forward or aft.

Longitudinal centre of floatation: See LCF.

Longitudinal Centre of Flotation (LFC) – The point about which the vessel tips and trims. It can be referred to as the tipping centre. It is the centroid (the centre of gravity of the waterplane area).

Longitudinal Centre of Gravity (LCG) – The longitudinal point through which the weight of the vessel is considered to act.

Longitudinal Framing – Framing, of a vessel’s hull, that goes fore and aft instead of transversely.

Longitudinal Stress – Stress that tends to deform the longitudinal form of a vessel or member.

Longitudinals – In steel construction, a term for light duty fore/aft strengtheners. Those hull framing members that run the length of the boat (i.e. chine, keel, sheer, battens).

Longliner – A vessel engaged in fishing with a string of hooks several miles long, so as to restrict the vessel’s manoeuvrability.

Longship – Norse warship c. 900 A. D. Rowed 40 to 50 oars and had one mast and square sail.

Longshore Man – Labourer on a wharf or dock side.

Look Out – Man posted to keep a continuous look out, and to report anything sighted. 2. The duty performed by a look out man.

Loom – To appear in sight. 2. The reflection of a light in the sky when the light itself is hidden below the horizon. 3. Indistinct but enlarged appearance due to mist. 4. The end part of an oar forming a hand-grip when feathering and rowing. Sometimes defined as all that part of the oar that is inside the rowlock.

Looming – Appearing unusually large due to mist or fog.

Loop of Retrogression – Apparent loop in path of planet, occurring when motion changes from direct to retrograde, or vice versa as viewed from Earth.

Loose – To let go the ropes confining a furled sail.

Loose-footed – Said of a mainsail that is hauled out on a boom, but not laced to it.

Lop – Small but quick-running sea.

Loran – A Long Range Aid to Navigation. A master and slave stations transmit synchronised signals which can be received by a special receiver on board ship. Since radio signals travel at a known speed, the difference in time at which the signals arrive at the ship can be converted into distance. Signals from two pairs of Loran stations can thus fix the position of a ship at ranges up to, and sometimes over, 6000 M.

Lorcha – Sailing craft of China Sea. European type of hull, Chinese mast and rigging, 60 to 80 ft. long.

L’Ordannance de la Marine. Important codification of law and practice of marine insurance compiled under supervision of M. Colbert in 1681. Still forms basis of modern procedure.

Lost Day – Day ignored when crossing Date Line from west longitude to east longitude.

Lost or Not Lost – Clause in a marine insurance policy covering interests insured after ship has sailed. Average is then payable even if ship was lost when policy was taken out, provided insurer was unaware of the loss.

Lough – Irish loch.

Low – Area of low barometric pressure. Cyclonic depression. 2. Said of gyro compass when its indications are lower than they should be.

Low Latitudes – Closer to the Equator; generally considered to be the areas of the Earth less than 30 degrees latitude.

Low Pressure – Atmospheric circulations rotating clockwise in the southern hemisphere generally associated with unsettled weather.

Low Water – Lowest level reached by a particular tide.

Lower Anchor – Stern anchor of a vessel moored in a river with head up river.

Lower and Dip – Order given when going about under sail in a boat with dipping lug. Sail is lowered a little, fore end of yard is dipped round mast to new lee side; tack is unhooked, passed abaft mast and rehooked; sail rehoisted.

Lower Boom – Originally, lower studdingsail boom. Now: boom projecting from ship’s side when in harbour. Fitted with lizards and ladders for securing and manning boats.

Lower Deck – Deck next below middle deck in three-decked ship; next below main deck in frigate; next below upper deck in corvette. In R. N. term is used to denote all ratings, as differentiated from officers.

Lower Mast – Principal mast, carrying other masts fitted above it.

Lower Topsail – The square sail set above the course sails (lowest) of a sailing ship, usually paired with an upper topsail.

Lower Transit – Passage of a heavenly body across inferior meridian of an observer.

Lower Unit – The part of an outboard engine below the power head.

Lowerer – Man stationed to lower a boat at davits.

Lowest Astronomical Tide (LAT) – under any predictable astronomical or meteorological conditions.

Lowest astronomical tide: See LAT.

Lowitz Arc – Inverted arc between mock suns, and touching halo at upper edge and, sometimes, in vicinity of horizon.

Low-Water Mark – Line along a coast, or beach, to which the sea recedes at low water of tide.

Loxodrome – Curve, or surface of a sphere, cutting all secondary great circles of the sphere at a constant angle. Curve will continually approach a pole of sphere, but will not reach it in a finite distance. Rhumb line.

Loxodromic Curve – Loxodrome. Rhumb line on surface of Earth.

LPG Carrier – A ship designed to carry LPG.

Lubber – A clumsy and unskilled man.

Lubber Line – Vertical line on fore side of inside of compass bowl, and in fore and aft line of ship. Compass reading in line with it is the direction of ship’s head.

Lubberland – Imaginary place of bliss where even lubbers are not a nuisance.

Lubber’s Hole – Trap-door in flooring of top of a mast, and just above lower rigging. Forms an entry into top as alternative to going by futtock rigging.

Lubber’s Point – Short projection aft from inside of compass bowl and in fore and aft line of ship. Has same purpose as ‘Lubber Line’.

Lubrication – The use of an agent such as oil, to prevent contact between surfaces; reduce friction, wear and heat; and remove foreign materials (metal shavings).

Lucas Sounding Machine – Special type of machine made for measuring depths up to 6000 fathoms. Modern type has motor for heaving up.

Luff – Weather edge of a fore and aft sail. 2. Weather side of any vessel: opposite to ‘Lee’. 3. Coming closer to wind. 4. Broadest part of ship’s bows. 5. A luff tackle.

Luff Hooks – Leech line leading from mainsail or foresail to chess trees. Has a hook in each end.

Luff Purchase – ‘Double Luff.

Luff Rope – Reinforcement rope sewn into luff edge of sail.

Luff Tackle – Purchase consisting of single and double blocks. Standing part is spliced round neck of strop of single block, so allowing purchase to be hauled ‘two blocks’.

Luff upon Luff – Purchase obtained by hooking block of one luff tackle to fan of another, so gaining power of 9 or 16.

Luffing Rule – Yacht racing rule that allows a yacht that is being overtaken on her weather side to haul to windward.

Luffing – The symptom of the sail shaking through improper trimming or pointing too high.

Lug – Lugsail. 2. Extremity of shackle through which pin is passed.

Lugger – Vessel having one or two masts and a lugsail on each. May carry two or three jibs.

Lugsail – Four-sided sail on a yard slung at a point one-third of length of yard from forward. May be ‘balanced’, ‘dipping’ or ‘standing’.

Lull – Temporary cessation of wind-force.

Lumber – Timber.

Lump Sum Charter – Hire of a ship for a stated period and for a stated sum of money.

Lump Sum Freight – Agreed sum to be paid for carriage of cargo, on discharge, whether part of cargo has been lost or not.

Lumper – Man employed in unloading ships in harbour, or in taking a ship from one port to another. Paid a ‘lump’ sum for services.

Lunar – Pertaining to Moon. Particularly applied to method of determining longitude by measurements of Moon’s distance from other heavenly bodies.

Lunar Cycle – Period of 19 years, after which full and new Moons will occur on same day of same months. Also known as ‘Cycle of Meton’ or ‘Metonic Cycle’.

Lunar Day – Interval between successive transits of Moon over any given meridian. Mean value is 24 h 54 m mean solar time.

Lunar Distance – Angular distance of Moon from one of 14 heavenly bodies formerly tabulated in Nautical Almanac. These bodies were Sun, four planets and nine selected stars.

Lunar Method – Determination of longitude by lunar distances.

Lunar Month – Interval between successive conjunctions of Moon and Sun. Mean value is 29 days 12 hours 44.05 minutes.

Lunar Observation – Altitude of Moon when taken for determining position.

Lunar Tables –. Logarithmic tables for correcting apparent distance of Moon from a heavenly body for refraction and parallax.

Lunation – Period taken by Moon to go through all her phases. Mean value is 29 days 12hrs. 44 mins. 2.87 secs. ‘Lunar Month.’

Lunisolar Constituent – Used in harmonic analysis of tides to represent the effect of variations in relative distance and declination of Sun and Moon.

Lunitidal Interval – Mean time interval between Moon’s transit at a place and occurrence of next high water following.

Luper – Swivel hook used for twisting strands together when rope making. Lurch. Sudden and long roll of a ship in a seaway.

Lurch – The sudden heave of a vessel.

Lustrum – Five-year period used when considering meteorological information extending over a considerable time.

Lute – To apply luting.

Lutine Bell – Bell of H. M. S. Lutine, formerly French La Lutine. Vessel was wrecked near Terschelling in 1799 while carrying £1, 400, 000 in gold. Bell was recovered in 1859 and is now at Lloyd’s in London. It is mounted inside Rostrum and is rung when news important to members is to be announced. It weighs 106 Ib.

Luting – Glue, varnish or waterproof barrier applied between joining pieces of timber in a construction.

Lying To – Said of a vessel when stopped and lying near the wind in heavy weather.

Lyle Gun – A device to fire a life line to a ship in distress.Lyra – Constellation south of Draco and Cygnus. Has one navigational star, Vega.



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