Finding your way underwater, preventing getting lost, and not having to navigate with aids like coral heads and sand ripples makes carrying a compass on every dive extremely important. But carrying the compass is only half the battle; you also have to know how to use the compass. Using a compass underwater is different than on land. There are many influences underwater that can cause problems when trying to swim in a straight line or when returning to the boat.
Many people are intimidated by compasses and think they are difficult to use, but that isn’t true at all; they are actually very easy to use and anyone can learn.
A majority of the compasses on the market today are what is called needle direct compasses. The compass has a magnetic needle that points north and a bezel that can be rotated around the needle. The bezel is marked from 0 to 360 degrees in a clockwise direction. The compass also has a line on its face, known as a lubber line, which is used to ensure that the compass is pointed in the same direction that your are going.