If you're a serious runner/swimmer/cyclist/surfer who likes to track workouts and already invested in the Apple ecosystem for messaging/music/etc and like the idea of leaving your phone at home.
It's not very good for tracking swimming stats. Honestly, I'm still looking for something that will track laps accurately and without a ton of fuss.
Yeah, back when I used to swim a lot I could never find anything that was any good at tracking swim distance either in a pool or open water.
I just got a pair of swim goggles with a tracker. About to test them at the pool. I don't have high hopes for them but at least they were purpose built with swimmers in mind.
It'll track heartrate, duration of workout, and a loose notion of distance at least.
It might be because it is one of the few trackers that can track laps in pools less than 14 meters. Most of the others watches don't allow that, which might be due to a difference in sensors and the way the tracking is done.