Something that has gps, can display a bit of a map, and is waterproof is somewhere between your two leagues and I think it's genuinely useful.
For those running, I can see it being useful as well. GPS for tracking the morning run, with zero need to carry your heavy phone with you. And (talking about apple watch specifically, as that’s the one I have experience with), you can even connect your wireless headphones directly and listen to music too without needing a phone.