RE: Lesson Learned the Hard Way: Compass
A GPS is an electronic device that works by "talking" with other electronic devices way up in the air. It can and will fail eventually. If you internal compass needed to be synched the GPS can easily get VERY confused, it KNOWS what direction your going because it is updating your position with respect to satellites, however this contradicts what the internal compass is saying. Poof, dualing information.
Heading into the woods without a compass is foolish, sorry to say it, but it is. Even better, two compasses. They are simple devices, that rarely fail. GPS is basically a little computer, the firmware could have bugs, batteries die, compass needs synch, satellites can't be found etc etc etc.