Speaking strictly in terms of flotation, I gotta go with Granny Rosie
on this one; a full-thickness wetsuit provides tons of flotation. It is
not, however, a PFD. It is also, IMO, not really good as foul weather
gear, except for short periods, like maybe Wednesday night
round-the-buoy racing. Even then, it's less comfortable and more
restrictive than some nice pile clothing under Gore-Tex outerwear. I
also agree that staying on the boat is best. Harness and tether are my
friends.