But here's a pic of some dude wearing one in the Volvo Ocean Race.
Part of the reason some people wear helmets in the Southern Ocean is to be able to see through the spray, which can be painful to look into with the wind.
Arrgh, he ain't be no real man matey.
This guy is wearing a helmet in the circumstances in which a helmet is warranted. The visor helps him to see better, and his head is protected.I just can't see wearing a helmet at the Butte.
In other circumstances, a helmet would have drawbacks: reduced peripheral vision (so much for watching those tell-tales), neck strain, reduced hearing, etc., and could contribute to an accident. And, if the helmeted sailor bonks someone else in the head ... well, at least it's not quite so bad as the boom.