I'm afraid I agree with MJ ... mind you Andy_RR has probably made the most pertinant post.
I used to work as a proffessional fisherman and shudder now to think of those times that I pee'd over the back in the dark of night, alone whilst the crew were drinking tea below deck. No lifejacket (impractical most of the time for commercial fishing) high seas, often out of the transport lanes ....
We did survival courses and I can tell you that getting into a liferaft even under controlled circustances back then as a fit 20 something was not at all easy. Having just survived a ditching, being older, worring about passengers, ect ect would almost make it impossible. It's not of course, but the odds are stacked against you!
It's interesting to note that in the Fastnet disaster, most of the casualties had abandoned their yachts for the ill percieved safety of flimsy little liferafts. Yes, liferafts are ok if you have room and enough spare weight. However, some sort of survival suit would be far more practical. Even wearing a wet suit would be better than nothing (might cause some second looks as you de-frock at L2K though
). We once picked up some drift divers who's support boat had suffered engine failure. They'd been in the water several hours in the early spring, and whilst cold, were not too the worst for it.
The sea like the air is not to be taken lightly, but again it all comes down to personal levels of acceptable risk. Who does the full bit when flying to Sandown? The risk is still there, but few bother as the hope for a quick pick up increases that acceptable risk (mind you in winter, the chances are still not brilliant even in the Solent).
SS