Those ocean temps are very dependent upon location. On Hatteras Island, mid-eighties are the norm on the extreme southern tip of the island at Hatteras Village. Midway up the island you start to see upper seventies. Occasional bouts in the upper sixties in summer are not unheard of on the northern end of Hatteras. Go further north still to Duck, Corolla and Southern Shores, and ocean temps that are downright cold by southern standards are the norm. Little to no influence from the Gulf Stream, which veered out to sea at Hatteras is the reason.
We went to Corolla on the Outer Banks in early June a few years ago and the ocean water was COLD. We stayed in the cement pond. Nice area though. We were wondering when in the hell the water actually gets warm....