Have you ever tried to hold your breath and dive without SCUBA equipment IRL? You don't die immediately when you dive, you know... ;D

I freedive in real life and I like the feeling of it in the game. The twitches of diaphgram, sound/feeling of heart beat and the slowly generating blackout is pretty close to IRL (I've almost passed out 2 times when trying new record IRL).

I like it as it is now, but if something has to be adjusted, I'd add stronger blackout effect and pulsation of it with the heart beat, also some cam shake could be added. But, especially change of sounds when the hypoxia becomes worse would be nice - the sounds should become quieter and you should start to hear a "sizzling" sound that becomes louder and louder until you pass out.

There are two types of ammo that you can use in scuba divers gun: underwater mags and normal STANAG mags, you have probably used wrong mags.

^ What he said.

armapirx, I'm gonna print your comment and attach it next to my screen when I'm playing COOP! lol