Knowing where something lies relative to the ship is fundamental. A bearing is the horizontal direction from one point to another, expressed in degrees from north.

Visual bearings are taken with an alidade or gyro repeater; radar bearings come from the radar display. True bearings refer to true north; magnetic and compass bearings require correction. Navigators use cross bearings to fix position and relative bearings to describe targets for collision avoidance.

A rapidly changing bearing on a radar contact usually means the other vessel will pass clear; a steady bearing with decreasing range signals risk of collision. Accurate bearings remain essential even in the age of GPS, especially when verifying electronic positions or operating in confined waters.

• Horizontal direction between two points in degrees
• Taken visually or by radar
• Used for position fixing and collision avoidance
• Steady bearing with closing range indicates danger