COMPASSES

Compasses are essential navigational instruments. While there are a variety of types of compasses, the card (magnetic) compass and the gyrocompass are most frequently used in boating. Magnetic compasses point to magnetic north rather than true north and the difference between them is called “variation” which differs from place to place. Onboard magnetic disturbances, called “deviation,” also affect magnetic compass readings. As charts are based on true directions, it is necessary to convert magnetic compass readings to true directions taking variation and deviation into account and vice-versa. Gyrocompasses on the other hand point to true north and are not affected by deviation and are usually found on large ocean going vessels. The compasses in my webstore at www.mountains-and-seas.com are all magnetic compasses. Some are hand held, the rest are to be attached to the boat. The Bushnell Bear Grylls Back Track D-Tour Personal Tracker is particularly useful to hikers as it allows one to retrace one’s steps.