I know in Canada there is nothing that can be done to stop your picture from being taken by anyone at any time. The law states that the only time pictures are not permitted is where there is an expectation of privacy. aka your home, washroom, change room, (You get the point) public places like beaches (Yes even nude beaches) is public and there is no expectation of privacy. so if someone was to take your picture they are allowed and you can do nothing to stop them. The only thing about this is, that picture is not permissible to be uploaded to any public forum without your consent. So if the person is only there to take pics that only they will ever look at then fine. but they cannot show the pic to anyone nor can the upload it without consent.
A nudist beach is a private setting. Everyone is showing her or his private parts. Making photos is only possible after getting consent. Anything else is voyeuristic behaviour. Of course you can make photos of the beach with nobody on it.
A nudist beach is a private setting.every nudist beach I have been on has been a public place. The issue of consent might well vary from country to country, in some places the consent us to publish. If people are taking general photos on the beach, or you happen to be in the background of a shot then I dont think you have much cause for objections. If someone is taking close up or candid shots without your permission then that is another matter, just as it might be if you were clothed. We can hardly argue that nudity/naturism is perfectly natural and then object if we happen to be caught in a photo while naked in a nudist beach.