I think Charleston is also a great option. Spent two weeks done there last January.
Its currently the off season but the weather is not bad. There is plenty of stuff to do, and the local food scene is great.
Anymore I basically travel to water because I enjoy fresh seafood. I learned that I really like Shrimp and grits. Anyway, Charlestown is nice because you could make the drive north to Myrtle Beach. Its only a couple hours, but I'd probably just stay in Charleston.