There are GPS running watches available. I just ran into a review.

I suspect that a lighter watch plus a GPS (plus a manual compass for backup) would be more useful. However, I don't use a GPS, since I far prefer map/compass navigation when off-trail to still another gizmo requiring batteries.

Note that the more functions on your watch, the more often you'll have to change batteries!
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May your trails be crooked, winding, lonesome, dangerous, leading to the most amazing view--E. Abbey