A lot has been written about nude beaches from a legal point of view, and many continue to have problems. But as a way of sort of tying together much of what I have talked about already, I offer you this link which I found interesting.
http://www.capitalsun.com/assmd.html
This is a beach in Maryland which I don't know much about, but because, as i think I mentioned earlier, Maryland's indecent exposure law is stricter than most i.e. it does not allow for simple nudity, the legal status of this beach is tenuous even though it is located on federal land. This is the interesting part, and I imagine somewhat unique given the legal climate. You would not see this problem in most other states except when locals complain. But in Maryland, State Law requires federal officials to act (acting concurrently now with state officials and laws) to insure that laws are not broken. But the specific language if you read this link is perpetually confusing -
neither encouraging nor discouraging nudity! In other words, get naked at your own risk.
A NPS (National Park Service) employee not involved in enforcement may come by and ignore you, while an NPS enforcement employee coming by 5 minutes later could cite you!
It must be really unnerving getting naked on this beach....
Klondike