Definition of Bearing

Bearing refers to the horizontal angle between the direction of a vessel relative to true north or to another vessel or point on the navigation chart.

Bearing is measured using a bearing compass from 0 degrees in the north or bow of a boat clockwise to the point or vessel of interest.

It’s essential in determining where your vessel is headed and how safe you are from collisions as you navigate towards your destination.

There are three key aspects of bearing with regards to navigation:

  • Heading: The direction in which the bow of the boat is facing in relation to north as the 0 degree starting point.
  • True bearing: The direction of an object in relation to true north, which is the direction of the Earth's geographic north pole. Locating two or more bearings from your vessel at the same time enables a navigator to identify where their vessel is (true bearing) without using a GPS.
  • Relative bearing: Determines the possible risk of collision with other vessels using the boat’s heading as the 0 degrees point of reference to measure the direction of the approaching vessel from port or starboard. When taking several relative bearings over a period of time, keep in mind that:
    • If the distance between two vessels decreases yet the relative bearing continues to vary, there’s less risk of collision
    • If the bearing is maintained as the distance between vessels decreases, there’s a high risk of collision

Relative bearings of both fixed landmarks and navigational aids, such as beacons are used together with nautical charts to determine the position of a vessel as well as in search and rescue operations.

To aid in correctly determining relative bearing, the correct navigation lights must be displayed on sea faring vessels and navigation aids—red for port and green for starboard.

Example of Bearing in a Sentence

"The pilot of the boat observed that the relative bearing of another boat was less than 180° and its distance was steadily decreasing, meaning they were on a collision course."

Synonyms: heading, orientation, direction

Related Terms for Bearing