Jeff,

My brother lives in Charleston and used to live on Folly beach. I have a TheMightyHobie18 I have left on the beach stick up for two years with no problems. Launching is a bit limited but there is access just north of the Holiday Inn (come down the main drag into Folly until you can't go anymore and turn left - it's a little less than .25 mile on your right). To launch there, you will need to get there early or late - cars park in there and will likely block the access from about 9am to 7pm. From a security standpoint, I would leave the boat amongst a bunch of other boats that are one or two jetties north of the access point (about 100 yards). You will have to take the trailer back with you. There is also a fee based state park at the south end of the island and they look like they have good access looking in from the water but I doubt they'll let anyone leave a boat.

Folly is a great place to sail out of and it is reasonable to sail north into Charleston Harbor from there and around all the historical sites. At the south end of the island there is a wide "folly" where it gets flat and shallow and the waves kick up high and just start to break. It's awesome to pull up the boards and surf through there at medium to high tide - then head towards the marina in the creek behind the Island for some smooth water sailing, head back out the channel to the south of the folly, and do it again. There are several active H18s and H16s out there - a lot more on the beach including some seasprays, and even a Supercat.

If you are intersted in a little more secure accomodations, James Island Yacht Club has a great cat friendly beach that launches right into the harbor accross the way from downtown. I have no idea what their dues might be.