Been running boats for years number one you don't go on the water without a life jacket. Sounds like the process of natural selection at its most basic level. There is no excuse. I also fly float planes but not without proper support equipment like a canoe/boat and proper life jackets. I paddle white water, I am a trip leader for wilderness trips and at no time do I or any of my team go on the water without life jackets period. Doesn't mater how good a swimmer you are a cramp can make it impossible to swim, an injury can make it impossible to keep your head above water in places you could normally wade safely.
Dennis