Also as far as I've heard if you do it right drowning can be fast. I haven't looked into it much myself and would definitely do research before committing to anything. But that said i as I've heard the best way to do it is to work yourself up, maybe run around or do jumping jacks to get your heart racing. Then exhale all of your breath before submerging yourself. Since your body is so worked up it will require more oxygen to replenish itself, so hopefully you will pass out in the water much faster and avoid suffering as much. But again this is just what I've heard, I'd look into it more myself if it was what I was seriously considering.