Letterboxing Store
Get Your "Get a Clue" Bumper Stickers Here!

magnetic declination

Since the earth's magnetic field is not constant, a compass needle doesn't actually point to the true geographic North pole, but aligns itself with the magnetic force at your location on the globe. Declination varies from 0 to 20 degrees in the continental U.S., and as much as 30 degrees in the populated regions of the world. Maps are oriented to Geographic North (also called "True North), so if accurate navigation is your aim, compass bearings must be adjusted to compensate for declination. Most letterboxers ignore magnetic declination and use Magnetic North when creating clues.








Glossary Index