Which U.S. island has 16 miles of pure, undeveloped beaches and is accessible only by boat or plane?

Beautiful island with the village and businesses at the south end. Only accessible by the state ferries or boats. It was where Blackbeard was captured.

Blackbeard was never taken captive. He was killed in his last battle .

And a killer surf spot known as Pony Pens... Where the wild horses are... Sharky spot though and I got "swirled" by something massive while sitting in the line-up one day...