I feel like we really have the technology available to prevent a lot of drowning. Maybe it's a sensor worn on the head that can send off an alarm after being submerged for x seconds.

Maybe a drone or fixed cameras running computer vision algorithms.

Those are just some example solutions. I'm sure you could come up with more after giving it some thought. I just would like to see something like this.

Or if nothing else how about public service ads that educate people what to look out for.