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I take a Casio Pathfinder PAG240 /out/ and love it, but they seem to be out of production as of a year or two ago. Damn shame. I see some on eBay.
Any rugged, waterproof Casio model with time, temp, altimeter, barometer, and digital compass ought to do. Note that the temperature readings on most watches are fairly approximate and the compass isn't to be used for serious navigation.