I used to sail barefoot, until I pulled my daggerboard up while hitting the beach at speed, a little too late, the boat stopped, my foot slid forward as the board was on it's way up and sliced my foot open just below my little toe. Took a trip to the Emergency room, 5 stiches and about a month off sailing to heal. Now I always wear Gill sailing boots.

As for sun protection, I hate wearing long pants and long sleeves when it's 80-90 degrees so I use Bullfrog #36 gell. It stays on all day, even with spray and sweat, but isn't as greasy as the Coppertone type stuff.