The other concern with a watched-based GPS is battery life. The Fenix line is the best in the business here. In full-blown GPS mode, where a reading is taken every second, I’ve gotten about 15 hours out of it. But there’s also an UltraTrac extended option, which records a location every minute. Garmin says you’ll get 50 hours, but I haven’t maxed it out yet. I used full GPS mode most of the time while elk hunting, and charged the watch every few nights with the USB cord and a solar charger. I spent 21 nights camped out, broken up in three legs over four weeks, and keeping the watch charged was never an issue.