Global positioning systems have revolutionized the way people get from point A to point B. Utilizing satellites and orbital data, GPS devices can ping these satellites and compute location anywhere on the planet. GPS-enabled maps are used in smartphones, car navigation systems and elsewhere. But before GPS became the primary navigational tool, people relied heavily on other aids, such as a compass.
Understanding how to use a compass can prove invaluable, especially when boating, hiking or engaging in other activities in the great outdoors.
Parts of a compass
Compasses feature various components. The most basic will have a ringed needle housing that is printed with the cardinal points N E S W for North, East, South, and West. Some also have degrees as markings; a compass pointing due North is at 0 degrees. A rotating ring with arrows or other line markings will be on the outer facing of the compass as well. Other compasses also may have a clear baseplate into which the compass is attached. The baseplate may have rulers for helping to calculate distance when used with the map’s scale and a directional arrow.
The compass has a magnetized needle that always points to magnetic North. It will be colored red or white. Magnetic North is not the same as True North. In fact, the two can differ by up to 20 degrees depending on where a person is on the surface of the Earth. For the most accurate reading, compass users will account for this difference, which is called ‘declination’; otherwise, they may end up many miles away from their mapped destinations. There also will be an orienting arrow. This arrow allows the base plate to be aligned with the magnetic needle. A travel arrow tells the direction a person should head.
Reading a compass
To read a compass, users must first make sure they are away from structures that can interfere with the compass reading, such as large metal structures or high-voltage power lines.
Place the compass on the palm of a hand at chest level. Watch for the magnetic needle to rest with the red tip pointing to North.
Turn the dial surrounding the compass until the orienting arrow is completely lined up with the magnetic needle. Once it is, the direction arrow on the baseplate of the compass will now indicate your heading.
Beginners should always practice using a compass and test their map-reading and navigational skills in a place they visit frequently. When using a compass, always be sure the direction traveled coincides with the direction of the travel arrow.