As a new member, I'm a little late to the party, but it's a good question and I wanted to contribute. Arousal certainly does happen, but in my experience, the feel of the sun and maybe a gentle breeze, is so incredibly exillerating on my body, being aroused is the last thing on my mind. I'm not there for sex, I'm there to enjoy not being bound by clothes. In addition, I don't want to interfere with anyone's right to enjoy the same feeling, so gawking is not cool. I used to enjoy nude recreation a lot, when I lived in California. I hate the Puritanical influence that seems so pervasive in the Middle West. That, and the weather!

The places that I have gone to, nothing happens. one was a beach in Fla, and the other place was a nudist campground. I do know of two other beaches in Michigan where I live that play does go on. both are public beaches, one is Federal and the other one is State. Illegal at both places. being nude will get you a ticket, fine, and you name in the Newspaper. any kind of sex will get you arrested, off to jail, ect. best just to keep your bathing suit on.

Cant imagine its a big deal...no pun intended. I plan to visit my first nude beach this summer at Gunsior beach in NY...anyone interested?

Not really unless it's a nude beach for swingers

I've only been to a few nude beaches on Oahu and most of those are gay hook up spots as well, so I do see that type of activity all the time, but it doesn't bother me. If any activity goes on with anyone else it's not out in the open.

There's rarely any sexual activity on the beaches themselves. I've seen guys rubbing sun cream into that area with just a little too much enthusiasm. I've seen the occasional semi-erection, clearly displayed without shame. The closest I've seen to people having sex on the beach itself was a naked couple 'spooning.' But they were just lying there in that position. No humping going on.

If there are sand dunes behind the beach, then they're frequently a very different story. There's often cruising/dogging type activities going on in those.

Unintended arousal? It typically depends on how you handle it. Cover it up or roll over onto your front, and nobody cares. Parade around, showing it off, and you'll get a different reaction.

If a guy gets "in shape" and he is a decent person...he goes to the water and refreshes himself; he wouldn't be the first...nor the last...to experience this. He also can turn over his butt to the sun and wait until his erection goes away.
No drinking / drugs in the beaches.
Getting aroused in a nude resort may get him banned.

No, there is not sexual acrivity in the nude beaches...here, in Australia, Argentina or in Europe.