I was watching an Apple Watch Series 2 preview on iMore and came across this screen shot
From the screen looks like:
_stroke type
_laps
_active vs total calories
_pace
_total time
-length, total yardage
_and my favorite: average heart rate
If this is all the info we get from a swim workout, I'll be satisfied.
There are other swim trackers out there that will go in much greater detail (breakdown of each lap by stroke type, lap time, fastest 100 yards, continuous swim without a break, average turn time, etc...). I currently use the MOOV activity tracker, and it's been great. However, the one thing most of these trackers lack is heart rate. Also---I was sick of having to switch out my Apple Watch with another tracker every time I went for a swim.