It was far from a life and death situation, as it was a highly controlled activity.

But it was meant to mimic a life and death situation for practice: Anyone who travel by helicopter in the North Sea are required to go through this course which includes an emergency water landing drill. It involves sitting inside this thing that is reasonably close to one of the common helicopter models used in the north sea. Same seats, same belts, and similar windows.

This "simlator" hangs from a crane over a pool. So that you can practice escaping from a ditched helicopter. "Brace brace brace!" dunk
This is done while wearing a survival suit that has a rebreather. Each passenger has a dedicated scuba frogman to make sure you don't panic and drown.

First dunk emulates a successful water landing. Helicopter remains floating for a while, but then goes under. Release window, unclamp, and swim out.

It gradually increases in fuckery, to the poin where it's emulating a helicopter that goes under right away and flips around as it does.

I'm fairly light weight, so this survival suit gives me a lot of buoyancy, and this collar-like thing around my neck tended to catch on the window as I was going through. In the beginning, this was not a problem, but it became a pretty big one on the last test.

The disorientation from being flipped made it hard to compensate for the extra buoyancy, so I got stuck, upside down in the water. I immediately knew what happened, but I remained calm, moved back a little bit. With one hand to keep track of the window, I used my other hand to pretty much pack and squeeze collar as close to my neck as possible, preventing it from catching. There was no panic, but there was a slight worry that the frogman hadn't intervened. Thanks to the rebreather I could stay pretty calm and focus on what needed to be done to get through the window.

When I reached the surface the frogman explained that he saw that I was having some problems, but decided to let me continue, as he saw that I was calm and reasonably in control. In a real scenario such as this, panic would've killed me.

Slow is smooth. Smooth is survivable.