Out of curiosity, how far can handgun ammo go underwater? I read somewhere that the bigger high power stuff is gone by like 3 feet but don't recall anything about underwater.
But I know that the use you mean is when its wet and not when you're off fishing with the glock.
I've never attempted it. I've heard from some people that the water muffles the shot and won't damage your ears, and I've also heard that it amplifies it and will blow out your ear drums. Supposedly the concussion can do damage to your organs too. Who knows what's true---and I don't feel like finding out.
One thing that would definitely be a bad idea: using JHP ammo underwater.