It USED to be, years ago, there was a bar on the other side of Cozumel, the rocky uninhabited side, where you could sunbathe nude. Mezcalito or something like that? It's been YEARS since we've been there though. I would say no with regard to Roatan, as it is a very conservative place. It's been years ago now, but Bare Necessities tried to run a nude excursion there and got in trouble with the authorities. They've been back since then I think, so maybe it's more accepted now. Don't know Costa Maya, never been there. I thought it was just a manufactured port, just some shops and a beach that they built there so ships could dock, but I have never been there.