Glossary Archive

A buoyant, wearable safety device designed to keep a person afloat in the water and reduce the risk of drowning.  A life jacket, also known as a personal flotation device (PFD), is an essential piece of safety equipment used in boating and other water-based activities. It is designed to provide buoyancy and keep the wearer’s...

Personal safety device attached to harness on lifejacket and to vessel strongpoint. Designed to keep you on board

An inflatable or rigid floating device designed to provide emergency refuge and safety for individuals forced to abandon a vessel at sea. A liferaft is an essential piece of safety equipment carried aboard most seagoing vessels, including commercial ships, yachts, and fishing boats. Its primary purpose is to serve as a temporary shelter and flotation...

A lighthouse is a tall structure with a bright light at the top, located on or near the coast, to serve as a navigational aid for ships at sea. Lighthouses help sailors and mariners to safely navigate through waters, especially in low visibility conditions or at night. The light emitted by a lighthouse can be...

Pronounced: LEE-mah The term for the letter L in the NATO Phonetic Alphabet.

A rope used on a boat for various purposes, such as securing the vessel to a mooring (mooring line), adjusting sails (halyard or sheet), towing another boat (tow line), or for safety purposes (lifeline). Lines are essential tools on a boat and come in different materials, lengths, and thicknesses depending on their intended use.

Navigational lines drawn on a chart, each representing a possible location of a vessel based on a single observation or measurement.  A line of position (LOP) is a fundamental concept in marine navigation used to determine a vessel's location. It is a line on a nautical chart along which a ship is known to be...

A permanent lean to one side or the other

The condition of a vessel leaning to one side due to an imbalance in weight or external forces.  A vessel lists when it tilts to port or starboard due to an uneven distribution of weight, such as cargo, fuel, or ballast, or as a result of flooding. Unlike rolling, which is a temporary motion caused...

Flag semaphore indicating the letter L.