Wearing a life jacket anytime one flies over or on water is a great idea but to really get the full benefit you need to take an egress course. As a very experienced scuba diver and under water hockey player ( you play on the bottom of a pool, holding your breath) I thought I did not need the egress course until my company sent me on it.
The first run all I had to do was un strap, go to the nearest door which was beside me and open it. How hard could that be ? Well it turns out it is really hard after you have been rolled over underwater a few times and left up side down. After numerous unsuccessful tries I was finally rescued, mad and embarrassed.
However by the end of the course no matter what they did to me I stayed orientated and easily escaped. On the last try I salvaged some dignity by tidying up the cabin before my escape and bringing an extra life jacket with me on my way out.
Bottom line: Simples, If I had crashed in the water the day before the course I probably would not be around to type this.......