Like doing anything else, i love to surf naked! However, unless you are on a soft-top board, you will realize very quickly why board shorts and rash guards exist! It doesn't take long for nipples and inner thighs to get rubbed raw by salt water and wax.
I tried to surf a few times on Waikiki Beach while I was in the Navy. I wore short swim trunks and no shirt. When I was done trying to surf, my t shirt was dotted with blood from my bleeding nipples! I later wore a t shirt but never really succeeded in surfing. I got up a few times and after dozens of attempts, hung up my rented surfboard and decided that when in Hawaii, I was much better at golf! haha But, if I was successful at surfing, I would definitely surf naked. Black's Beach (San Diego) and San Onofre State Beach, Trail 6 (San Clemente), sees a lot of naked surfers, male and female!
When I lived on Oahu, I used to go to a place called Goat Island (Mokuauia Islet Seabird Sanctuary) just offshore of Malaekahana State Recreation Area outside of Laie. On the west side of the island was a very nice sandy half-moon bay beach protected by a natural reef that was commonly clothing optional. The other side of the island however got some pretty gnarly waves, and was a common spot for surfers. It wouldn't happen often, but occasionally you would see a nudist surfer.
John aka cobeachbum