There are a lot of swamps, marshes and sloughs on the island, this can really limit your movements on foot depending on how wet you want to get. At the minimum a good pair or boots, however a pair of hip waders or chest waders will come in handy. Plan on having your boat go high and dry unless you are anchoring in a channel and using a tender to get to shore. Some of the camp sites are in low points and flood in severe rain, taking a scouting trip down there this winter/spring will give you a better idea of which camp sites are the better ones to reserve.