RE: repost: the life jacket problem
The suggestion that o2bnme offers concerning the use of a helmet makes real sense. I wear a helmet whenever I windsurf regardless of the windspeed or sail size. Although many frown on the use of a helmet, I personally feel safer and more secure using one, kind of like wearing a seatbelt while driving a car. Most of the time it could be considered unnecessary, until that time when an unexpected accident comes out of nowhere.
I wear the Gath helmet that was originally designed for surfing. It fits very close to your head and includes closed cell foam inside that doesn't absorb water. In addition to impact protection, a helmut offers a lot of warmth in colder conditions. Also, they offer a buffer against sudden water intrusion into your ears that can break an eardrum.