Hey it happened to me once, 2/18/2012, when I hit the water it was 43 degrees and I thought this isn't as bad as I thought it would be. Didn't have a life jacket on but my friend had the fore sight for us to get them quickly, if not for him and God's grace I'd have never made it to the bank, certainly not without the life jacket, and the swim wasn't really that far. Hypothermia set in so fast it was surprising to say the least, just before I got to the bank my muscles were locking up and I lost the ability to swim. Once on the bank it felt like I was breaking concrete just to standup and move. My prayers go out to the family. To everyone else, trust me you won't have a chance without your life jacket. Even then it will be hard enough to survive the cold water, but at least you'll have your best chance.