Glossary of Nautical Terms - L

L

Ladder

On board a ship, all "stairs" are called ladders, except for literal staircases aboard passenger ships. Most "stairs" on a ship are narrow and nearly vertical, hence the name. Believed to be from the Anglo-Saxon word hiaeder, meaning ladder.

Laid up

To be placed in reserve or mothballed. The latter usage is used in modern times and can refer to a specific set of procedures used by the US Navy to preserve ships in good condition.

Laker

Great Lakes slang for a vessel who spends all its time on the 5 Great Lakes.

Land lubber

A person unfamiliar with being on the sea.

Lanyard

A rope that ties something off.

Larboard

Obsolete term for the left side of a ship. Derived from "lay-board" providing access between a ship and a quay, when ships normally docked with the left side to the wharf. Replaced by port side or port, to avoid confusion with starboard.

Large

See by and large.

Lateen sail or Latin-rig

A fore-and-aft triangular sail set on a long yard mounted at an angle to the mast.

Lateral system

A system of aids to navigation in which characteristics of buoys and beacons indicate the sides of the channel or route relative to a conventional direction of buoyage (usually upstream).

Launch

1. Traditionally, a launch was the largest ship's boat carried by a warship.

2. In modern usage, a large motorboat.

3. To dispatch a ship down a slipway, prior to fitting-out and commissioning.

Lay

To come and go, used in giving orders to the crew, such as "lay forward" or "lay aloft". To direct the course of vessel. Also, to twist the strands of a rope together.

Lay day

An unexpected delay time during a voyage often spent at anchor or in a harbor. It is usually caused by bad weather, equipment failure or needed maintenance.

Laying down

Beginning construction in a shipyard.

Lazaret (also Lazarette or Lazaretto)

1. A small stowage locker at the aft end of a boat.

2. A ship or building used for quarantine of sick patients.

3. An area on some merchant ships where provisions are stored.

4. In modern shipbuilding and on powerboats of all sizes, the location of the steering gear equipment for the vessel.

Lazy jacks, lazyjacks

A network of cordage rigged to a point on the mast and to a series of points on either side of the boom that cradles and guides the sail onto the boom when the sail is lowered.

Lead

1. A plummet or mass of lead attached to a line, used in sounding depth at sea.

2. In former usage, to estimate velocity in knots.

Leadline (also sounding line)

An instrument used in navigation to measure water depth; the line attached to a lead.

Leadsman

A sailor who takes soundings with a lead, measuring the depth of water.

League

A unit of length, normally equal to three nautical miles.

Leech

The aft or trailing edge of a fore-and-aft sail; the leeward edge of a spinnaker; a vertical edge of a square sail. The leech is susceptible to twist, which is controlled by the boom vang, mainsheet and, if rigged with one, the gaff vang.

Lee side

The side of a ship sheltered from the wind (cf. weather side).

Lee shore

A shore downwind of a ship. A ship which cannot sail well to windward risks being blown onto a lee shore and grounded.

Leeboard

A fin mounted on the side of a boat (usually in pairs) that can be lowered on the lee side of the ship to reduce leeway (similarly to a centerboard, which see).

Leeway

The amount that a ship is blown leeward by the wind. See also weatherly.

Lee-oh or hard-a-lee

The command given to come about (tack through the wind) on a sailing boat.

Leeward (/ˈluːərd/ in nautical use)

In the direction that the wind is blowing towards.

Length between perpendiculars, also p/p, p.p., pp, LPP, LBP or Length BPP

The length of a vessel along the waterline from the forward surface of the stem, or main bow perpendicular member, to the after surface of the sternpost, or main stern perpendicular member. Believed to give a reasonable idea of the vessel's carrying capacity, as it excludes the small, often unusable volume contained in her overhanging ends.

Length overall, or LOA

The maximum length of a vessel's hull measured parallel to the waterline, usually measured on the hull alone, and including overhanging ends that extend beyond the main bow and main stern perpendicular members. For sailing vessels, this may exclude the bowsprit and other fittings added to the hull, but sometimes bowsprits are included.

Let go and haul

An order indicating that the ship is now on the desired course relative to the wind and that the sails should be trimmed ('hauled') to suit.

Letter of marque and reprisal or just Letter of marque

A warrant granted to a privateer condoning specific acts of piracy against a target as a redress for grievances.

Liberty

A relatively short period when a sailor is allowed ashore for recreation. See also shore leave.

Lifebelt, lifebuoy, lifejacket, life preserver, personal flotation device

A device such as a buoyant ring or inflatable jacket which keeps a person afloat in the water.

Lifeboat

1. Shipboard lifeboat, kept on board a vessel and used to take crew and passengers to safety in the event of the ship being abandoned.

2. Rescue lifeboat, usually launched from shore, used to rescue people from the water or from vessels in difficulty.

Liferaft

An inflatable, covered raft, used in the event of a vessel being abandoned.

Lift

An enabling wind shift that allows a close hauled sailboat to point up from its current course to a more favorable one. This is the opposite of a header.

Lighter

A flat-bottomed barge used to transfer goods and passengers to and from moored ships, traditionally unpowered and moved and steered using "sweeps" (long oars), with their motive power provided by water currents.

Line

The correct nautical term for the majority of the cordage or "ropes" used on a vessel. A line will always have a more specific name, such as mizzen topsail halyard, that specifies its use.

Line astern

In naval warfare, a line of battle formed behind a flagship

Liner

1. During the Age of Sail, a ship-of-the-line, a major warship capable of taking its place in the main battleline of fighting ships.

2. Any cargo or passenger ship running scheduled service along a specific route with published ports of call, excluding ferries and other vessels engaged in short-sea trading. When referring to cargo ships, liner in this sense contrasts with tramp, which refers to a ship engaged in spot-market trade that does not follow a regular schedule or make regular calls at specific ports. When referring to passenger ships, liner in this sense refers to ships providing scheduled transportation between regular ports of call and excludes cruise ships, which voyage merely for recreational purposes and not primarily as a form of transportation between ports.

3. Ocean liner: Any large and prestigious passenger ship, including cruise ships.

List

A vessel's angle of lean or tilt to one side, in the direction called roll. Typically refers to a lean caused by flooding or improperly loaded or shifted cargo (as opposed to 'heeling', which see).

Loaded to the gunwales

Literally, having cargo loaded as high as the ship's rail; also means extremely drunk.

Lofting

The technique used to convert a scaled drawing to full size used in boat construction.

Loggerhead

An iron ball attached to a long handle, used for driving caulking into seams and (occasionally) in a fight. Hence: 'at loggerheads'.

Long stay

The relative slackness of an anchor chain; this term means taught and extended.

Loose cannon

An irresponsible and reckless individual whose behavior (either intended or unintended) endangers the group he or she belongs to. A loose cannon, weighing thousands of pounds, would crush anything and anyone in its path, and possibly even break a hole in the hull, thus endangering the seaworthiness of the whole ship.

Loose footed

A mainsail that is not connected to a boom along its foot.

Lubber's hole

A port cut into the bottom of the mizzentop (crow's-nest) allowing easy entry and exit. It was considered "un-seamanlike" to use this easier method rather than going over the side from the shrouds, and few sailors would risk the scorn of their shipmates by doing so (at least if there were witnesses).

Lubber's line

A vertical line inside a compass case indicating the direction of the ship's head.

Luff

The forward edge of a sail.

Luff up

To steer a sailing vessel more towards the direction of the wind until the pressure is eased on the .

Luffing

1. When a sailing vessel is steered far enough to windward that the sail is no longer completely filled with wind (the luff of a fore-and-aft sail begins to flap first).

2. Loosening a sheet so far past optimal trim that the sail is no longer completely filled with wind.

3. The flapping of the sail(s) which results from having no wind in the sail at all.

Luff and touch her

To bring the vessel so close to wind that the sails shake.

Lying ahull

Waiting out a storm by dousing all sails and simply letting the boat drift.

Lumber hooker

A Great Lakes ship designed to carry her own deck load of lumber and to tow one or two barges. The barges were big old schooners stripped of their masts and running gear to carry large cargoes of lumber.

Lugger

A small sailing vessel with lugsails set on two or more masts and perhaps lug topsails, widely used as traditional fishing boats, particularly off the coasts of France, England and Scotland.

Lugsail

A four-sided fore-and-aft sail supported by a spar along the top that is fixed to the mast at a point some distance from the center of the spar. See Lugger.