This is probably not really a big issue, since the situation will not occur very often for most players. But regarding Arma's claim to be ultra-realistic in so many aspects, doesn't it seem a bit unrealistic that you can dismount a (crashed) vehicle underwater easily even though there are already tons of water above you and the pressure would make it impossible to open the doors before the vehicle is completely filled with water?

And yes, the Battlefield 4 Trailer inspired me to try this out ;)