I can't say enough great things about this camping experience! You can rent canoes from the Visitors Center for $25 a night and canoe out to campsites 1-5. Or you can launch your own canoe and embark to campsites 6-14. Either way, all sites are super private and on the water. Sites have a fire ring and picnic table. Many can accommodate large groups. Fantastic swimming and fishing opportunities. You can also do the Shipyard Island Canoe trail which begins directly across from the visitors center.
Canoe out to a primative campsite on your own island! Explore the salt creeks on the interior of the islands in the lagoon, swim alongside dolphins, and check out the shell middens constructed by the indigenous people of the area.
The Atlantic side of the barrier strip has some great beaches and some decent surfing in some areas. Head far enough and you can enjoy it au naturale at the clothing optional beach. This national park has a lot to enjoy.