4. NOT GETTING LOST
Oh, yeah, a handheld GPS is good insurance against this, too. Often there are audio clues that help us keep our bearings: traffic noise from a nearby highway, planes taking off and landing at a nearby airport; trains passing on a railway. When you're hunting unfamiliar ground or vast tracts of land where such references are unavailable, however, a GPS is good insurance. It tells you where you are, how far you've been, how far you've got to go and that sort of thing. I also carry a Brunton compass in my pack, but mainly for just-in-case. The Oregon 400t has a compass, but I figure if the GPS goes out, its built-in compass is likely to as well. Still, I carry two AA backup batteries.