When working at Channel Islands Nat'l Park, we were required to take training in emergency ditching procedures periodically. We did a lot of over water flights (! - I guess that'shy they are islands....) in both fixed wing and helicopters.

At one of these sessions, we used an invertible cage in a swimming pool. The key was to get a grip on the door latch preimpact, so that you maintained your orientation as you inverted and went in the water. If the latch was to you left, you reached across your body and gripped with the right hand. Once everything had stopped moving, and that is critical, you opened the door and exited.

Easy enough and kind of fun in a swimming pool. I've never had a chance to try it for real, nor have I talked with anyone who has.