They have an air show in spring/ summer, I don't remember excactly, but it's pretty good.
yeah the air show is pretty good usually take off from Shaw AFB in Sumter... fighters make it to the beach in 15min buzz the beach. Hunting ton by the jettys is where they usually make the turn.... knew a non-com who made the ride... said it was cool!
The best time to visit depends on what you want to do. I personally prefer the spring time. In the low country, the azaleas are blooming and festivals abound everywhere. Unfortunately the spring seems not to last very long. It seems to go from winter to summer way too quickly.