My wife and I go to Charleston often and our #1 place to go is the Boathouse
on the IOP (Isle of Palms) at the bridge (at Breach Inlet) which connects to Sullivan's Island. You may see a few sailboats docked from the ICW
and you can have a drink before dinner, outside on the deck
and watch the dolphins
. Be sure to call ahead for reservations, it is very popular with the locals. Our favorite dish is the Fried Scallops with Blue Cheese coleslaw. We actually split the dish and still have plenty to eat. Don't go to the Boathouse downtown. The one at the IOP is much better.
While you are in Charleston, don't miss breakfast at the Variety Restaurant
which is located at the City Marina on the Ashley. Great View and lots of sailboats and parking is free if you eat at the Variey. They have the best grits in the south and you will see lots of sailors and locals.