I personally will rarely surf with no leash and only when it is not crowded and waves are small enough that I am fairly certain my board will never escape me. I see some people surf with no leash regularly and they are usually really good and it is not a big problem. This weekend I was surfing at Pacifica (because I was surfing with a girl who was scared of OB before you judge) and some guy paddled out on a longboard with no wetsuit. I was initially somewhat impressed because it is still pretty chilly out there. Anyway I caught the first wave of a set and look back to see a longboard flying at me in the wash of the second wave in the set. I pushed my board out of the way to avoid dings and grabbed it to give it back to whoever it belonged to. Then I see the guy with no wetsuit swimming towards me, he doesn't have a leash on his foot and the board doesn't have a leash on it so I realize he came out wetsuitless and leashless on a packed day full of beginners. So while he can see me holding his board I aimed it away from the one person inside of me and pushed it into the next waves whitewater which took it to the beach. He was pissed that I pushed it in but he didn't come back out after his swim so I think I won. What would you have done and what do you think about surfing sans leash?