Glossary Archive

The difference in height between HW and LW on a Mean (average) neap tide.

When the difference between high and low water is at its smallest, typically occurring twice a month during the first and third quarters of the moon. A neap tide is a natural tidal phenomenon that occurs when the gravitational forces of the moon and the sun are at right angles relative to the Earth. This...

Sometimes used to describe wind strength approaching a Gale.

The Northern Lighthouse Board is a maritime organisation responsible for maintaining lighthouses and navigation aids in Scotland and the Isle of Man. Established: The Northern Lighthouse Board was established in 1786 and serves a similar purpose to Trinity House but specifically covers Scotland and the Isle of Man. Responsibilities: NLB is responsible for the operation...

Flag semaphore indicating the letter N.

International Morse Code sequence representing the letter N.

A Notice to Mariners is an official publication issued by maritime authorities to provide important information and updates regarding navigational hazards, changes to navigational aids, and other relevant information that may affect the safety of navigation in a specific area. This information is crucial for mariners to stay informed and make necessary adjustments to their...

The National Oceanic and Atmospheric Administration is an American scientific agency within the United States Department of Commerce that focuses on the conditions of the oceans, major waterways, and the atmosphere.

A radio transmitter at a fixed location that emits signals in all directions, used in marine navigation to help vessels determine their position relative to the beacon. A Non-Directional Beacon (NDB) is a fundamental navigational aid in the maritime world, providing mariners with a reliable method to ascertain their position and course. Unlike directional or...

An intergovernmental military alliance established in 1949 aimed to ensure the collective defence of its member state through political and military means. NATO was founded in the aftermath of World War II, with the North Atlantic Treaty (also known as the Washington Treaty) signed on April 4, 1949. Its primary purpose was to create a...