A compass is used for underwater and topside navigation. Your instructor will teach you how to navigate with a compass during your open water dives.

Compasses must be held level to provide an accurate reading. The best compasses are filled with water, which dampens needle movement and prevents the compass from breaking under the pressure encountered under water.

The needle points to magnetic north. This part of the compass is magnetic, so to ensure its accuracy, hold the compass away from other magnetic objects such as cylinders, dive knives, and other compasses.