The only thing I can think about when I see pictures of naked guys on beaches is where do they keep their wallet and keys? Answer? Obviously it's in the ass. Though it does make it difficult when a guy wants to buy a cold snack from the vendor at the beach and has to jam his ass into a credit card reader.
I guess the answer is actually the same place as they'd put their wallet and keys if they were wearing a swimsuit, because generally swimsuits (except for the slutty gay kinds that have a spot to stash a condom) don't have pockets.
And I guess that nude beaches aren't inherently sex dens. But half and full boners would beg to differ. I've never been to one though. Sex den, yes. Nude beach, no. I would rather undress someone with my eyes. I lack the skill to dress someone with my eyes. I have tried on occasion and one can't unsee.
My biggest objection to nude beaches is they make nudity less obscene and more mundane. My biggest draw to them is the ability to appreciate the human form in all its natural glory, sort of like a figure drawing class with better lighting.
You may not be anywhere near a nude beach. Or a nude lakeside. But there are nude spots and groups of some kind most everywhere. Just figure out where to put your damn keys and wallet so they're safe. And if you're on the beach and your ass is full of cock, then maybe have another friend hold your stuff.
Though if you're on a nude beach and your ass is full of cock, you're more likely remembering a porn movie you saw once because nobody is that lucky for real.