Good point. Assuming you survive the ditching (and statistics show that most ditchings are sucessful according to the NTSB), thats when your problems start.
I watched a video on a North Sea survival course of Duncan Goodhew and Sharon whatshername (Olympic swimmers) dumpped in a swimming pool at average UK water temps, and after 10 minutes they were both useless, and they are sh*t hot swimmers.I can vouch that the costal waters are still bloody cold, even in a 5mm wetsuit, the Channel Light Vessel is showing 10°C at the moment. There are some interesting graphs around showing survival time vs water temp, and its not very long at these temps.
EA