A liferaft or dry suite is the only guarantee of survival time in the water.
I like the sound of a dry suite!!
When I cross the water I always find it reassuring to keep a look out for the ships below (a bit like always keeping an eye out for an open field over land). Probably wouldn't do much good but I think it gives me a better chance of getting scooped from the drink (assuming one landed parallel to the ship not in front!)
Does anyone know if a Mayday made over the air would ever be relayed to nearby vessels or is that wishful thinking?