Water to 30 meters, but what about SALT water??
While i'm no expert, fresh water and salt water are entirely different beasts. I got a nice FitBit a couple of years ago, and after being wonderful for over a year, a dip in the warm waters off Hawaii killed it for good. Before that I had been taking showers and other stuff.
All the pictures in the "event" showed swimmers in nice fresh water pools. A bunch less hostile!