Actually, the altimeter and barometer are measured via air pressure. You have to adjust your altitude at a known altitude on the map because of changes in air pressure. If your camp falls during the night, you know a storm is coming!

+2 on always having a manual compass with you!


Edited by OregonMouse (03/10/11 10:07 PM)
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May your trails be crooked, winding, lonesome, dangerous, leading to the most amazing view--E. Abbey