Ask HN: Underwater cell phones?

I've been spending a lot of time swimming lately, at least three hours per day. Unfortunately as of today I can no longer be inaccessible to the outside world for so long, and need to find a way for important calls/txts (mostly txts) to catch my attention when I'm swimming laps. I was thinking some sort of a bluetooth device, but I'm not sure the distance would work, since I'm both underwater most of the time, and at random points along a 50-ft pool.

Any suggestions?