I don't recommend Bird Island. My understanding is that the atmosphere has changed and C/O is not permitted. However, just off of Wrightsville Beach is Masonboro Island. You can take a water taxi from in front of the Blockade Runner Hotel. It makes a trip in the morning and picks up sometime later in the day. The island is not inhabited and if you walk a ways up the beach away from other groups you can be nude.

tanjohn