Here in the Channel Islands, it is very simple. If you go into the water wearing a wetsuit, you have a chance to survive. One gent drifted for two days until he fetched out on an oil rig (summer conditions - water temp in the 60s). If you are not wearing a wet suit you will die. A PFD just makes it easier to find and recover your corpse.

There was an instance a few years back where a fishing boat sank with something like eight or so people on board. The survival was as outlined above; all the survivors were wet suited. One fiance, in a wet suit, clung to his fiancee, unwetsuited, until she slipped from his arms into the depths. The ocean is very unforgiving.

Anybody got something more cheerful to discuss?