St Augustine option
North Beach Campground was fantastic last year. I know they got hit by the hurricane this fall, but they should be back open again. Very short (3-4) minute walk from our site, across a 2 lane road to the Atlantic Ocean. Behind the campground is the salt water North River... gorgeous piece of water. The campground literally sits on a spit of land between these two bodies of water. The campground itself is GORGEOUS with large sites with plenty of natural vegetation between the sites to give a very private feel.
The only downfall is that the entire campground is sand. Pets or kids will track sand EVERYWHERE. People with long term sites usually place out plastic sheeting or large pieces of outdoor carpet to cut down on the sand. Then again... you are at the beach, clean it out when you get home!
While we don't love St Augustine as much as other cities (Charleston and Savannah, for example), this is a gorgeous campground and has amazing water access.
Beautiful drive along the water to Jacksonville to the north, short trip to St Augustine to the south.
http://northbeachcamp.com/