Bearing

The direction or angle between a reference point, typically true north, and an object or destination, usually expressed in degrees.

A bearing in maritime navigation refers to the horizontal angle between a reference direction, commonly true north or magnetic north, and the direction to a specific object or destination. Bearings are typically measured in degrees, with 000° corresponding to north, 090° to east, 180° to south, and 270° to west. They are essential for determining a vessel’s course or identifying the location of objects relative to the ship. Bearings can be taken using various instruments, such as a compass or a radar, and are often classified as either true bearings (relative to true north) or magnetic bearings (relative to magnetic north, which varies depending on location due to the Earth’s magnetic field).

In practical terms, a navigator might take a bearing on a lighthouse or another landmark to establish the vessel’s position or to ensure that the ship is on the correct course. Bearings can also be relative, meaning they are measured from the ship’s current heading rather than from a fixed reference like true or magnetic north. For example, a relative bearing of 090° would indicate that the object is directly to the right of the vessel, regardless of the ship’s heading. Understanding and correctly interpreting bearings is crucial for safe and effective navigation at sea.

Bearings and courses are given in a 3-figure notation, i.e. 090°. When using a bearing on a magnetic compass, variation and deviation may need to be considered to ensure the bearing lines up with the required true bearing for use on charts.