Absolute 300px|A compass rose, showing absolute bearings in degrees. In nautical navigation the absolute bearing is the clockwise angle between north and an object observed from the vessel. If the north used as reference is the true geographical north then the bearing is a true bearing whereas if the reference used is magnetic north then the bearing is a magnetic bearing. An absolute bearing is measured with a bearing compass.   Relative In nautical navigation the relative bearing of an object is the clockwise angle from the heading of the vessel to a straight line drawn from the observation station on the vessel to the object. Search and rescue A bearing can be taken to a person or vessel in distress in order to go to their aid. Grid bearing A grid bearing is measured in relation to the fixed horizontal reference plane of grid north, that is, using the direction northwards along the grid lines of the map projection as a reference point, while a compass bearing, as in vehicle or marine navigation, is measured in relation to the magnetic compass of the navigator's vehicle or vessel (if aboard ship). It should be very close to the magnetic bearing. The difference between a magnetic bearing and a compass bearing is the deviation caused to the compass by ferrous metals and local magnetic fields generated by any variety of vehicle or shipboard sources (steel vehicle bodies/frames or vessel hulls, ignition systems, etc.)
Absolute 300px|A compass rose, showing absolute bearings in degrees. In nautical navigation the absolute bearing is the clockwise angle between north and an object observed from the vessel. If the north used as reference is the true geographical north then the bearing is a true bearing whereas if the reference used is magnetic north then the bearing is a magnetic bearing. An absolute bearing is measured with a bearing compass. A grid bearing (also known as grid azimuth) is measured in relation to the fixed horizontal reference plane of grid north, that is, using the direction northwards along the grid lines of the map projection as a reference point. A compass bearing, as in vehicle or marine navigation, is measured in relation to the magnetic compass of the navigator's vehicle or vessel (if aboard ship). It should be very close to the magnetic bearing. The difference between a magnetic bearing and a compass bearing is the deviation caused to the compass by ferrous metals and local magnetic fields generated by any variety of vehicle or shipboard sources (steel vehicle bodies/frames or vessel hulls, ignition systems, etc.) Relative In nautical navigation the relative bearing of an object is the clockwise angle from the heading of the vessel to a straight line drawn from the observation station on the vessel to the object. Search and rescue A bearing can be taken to a person or vessel in distress in order to go to their aid. 
A
A grid bearing (also known as grid azimuth) is measured in relation to the fixed horizontal reference plane of grid north, that is, using the direction northwards along the grid lines of the map projection as a reference point.
A
A compass bearing, as in vehicle or marine navigation, is measured in relation to the magnetic compass of the navigator's vehicle or vessel (if aboard ship). It should be very close to the magnetic bearing. The difference between a magnetic bearing and a compass bearing is the deviation caused to the compass by ferrous metals and local magnetic fields generated by any variety of vehicle or shipboard sources (steel vehicle bodies/frames or vessel hulls, ignition systems, etc.)
D
Grid bearing
D
A grid bearing is measured in relation to the fixed horizontal reference plane of grid north, that is, using the direction northwards along the grid lines of the map projection as a reference point, while a compass bearing, as in vehicle or marine navigation, is measured in relation to the magnetic compass of the navigator's vehicle or vessel (if aboard ship). It should be very close to the magnetic bearing. The difference between a magnetic bearing and a compass bearing is the deviation caused to the compass by ferrous metals and local magnetic fields generated by any variety of vehicle or shipboard sources (steel vehicle bodies/frames or vessel hulls, ignition systems, etc.)