Definitions 1: General Mariner Terminology

The change in the compass reading caused by the magnetic influence of the metal equipment aboard a vessel

Difference between true north (using earth's axis of rotation) and magnetic north (using earth's magnetic field)

A seagoing measure of six feet

The distance north or south of the equator measured and expressed in degrees

One minute of latitude, approximately 6076 feet: about 15% longer than statute mile of 5280 feet

The art and science of conducting a boat safely from one point to another

Two or more bearings of known aids to navigation noted and plotted on a chart to determine the ship's position

The determination of a ship's position by observation of celestial or terrestrial objects

Artificial objects and supplemental natural landmarks indicating safe and unsafe waters

A near-shore navigation method: movements are directed by reference to landmarks/other aids to navigation and soundings

An anchored float used for marking a position, hazard or shoal on the water or for mooring

A map for use by navigators, showing aids to navigation, shoals, water depth, etc.

Measurement device on a chart; indicates true and magnetic north, magnetic variation, its annual change, and print year

The direction in which a boat is steered

The direction in which a vessel's bow points at any given time

Method of navigation: ship position is found using a previous position of vessel, direction, speed, and time since then

The direction of an object expressed either as a true bearing, or as a bearing relative to the heading of the boat

The distance in degrees east or west of the meridian at Greenwich, England