Been using an Apple Watch hand-me-down for a few days and actually thinking about getting a 42mm Series 2.

I'm curious if anyone has any experience hiking the trail with one of these. It seems it would be nice to be able to pin a waypoint or track a route using Gaia GPS, which can be controlled via the watch. I believe you can also glance at a map to see your location once the watch grabs the map from the phone. I am curious how long the batteries of both the watch and phone would last under such use. I know I can get a 10,000 mAh battery to recharge them at minimal cost. However, if using them while hiking the trail drains the batteries in a just couple of hours, it may not be worth the trouble. How well do they hold up?

Note that I always take a printed map. The watch/phone would be more for fun and convenience/tracking.