My Garmin Epix watch is practically bullet proof. I've dove with it in open ocean. I've jet skied with it. I rock climb with it. It's surived 108miles of Unbound (the race) in mud, sun, sweat. I've water rafted with it. I've swam in crappy lakes, streams and jumped off cliffs. Hottubs? also no problem.
Zero chance a iWatch would ever survive these conditions.
Oh and despite all of this, the screen has not scratched, not even a little. Plus it has 5-10 days of battery life... and did I mention I always have a flashlight on me?