I recently found a little glitch on the xbox 360
What you will need is...
A car
Rebreather
How to do it...
Simply put on your rebreather and hop in to a car and drive into the sea I found it best by getting a friend in a cargobob and taking you high at sea then dropping once you are in the sea the rebreather bar should go down and as it near the end it stops and you don't lose health or drown the downside to this glitch is if you get out the car the rebreather bar starts to go down again I guess this glitch is for just exploring and can fool some people to how you are their so long
Enjoy this glitch if you try it out.