I just got the resort activity schedule faxed to me for next week. (We arrive on Tuesday.)
There are several activities with the naturalist that would probably be great at this time of the year, especially with the beautiful weather that you should be having! The resort also now has a mini-bus tour of Hilton Head Island; I took it last year and learned much about the history, etc. of the whole island.
You should also be able to spend time at the pool or beach (although actually swimming in the ocean might be a bit too brisk), and of course there's always shopping!
Oh, and if you've never done the dolphin tour offered by the resort, I would highly recommend it.
Have a wonderful time!
