We did the Boggy Creek airboat ride in January. They're a very friendly bunch and we were well looked after by the owner, Margie.
Although it wasn't a particularly cold day, it was freezing out on the water. There are blankets available to take out and Margie advised us to wrap ourselves in them rather than just drape them across ourselves. We'd also worn plenty of layers and I'm really glad we did - it would have been a miserable experience otherwise, but we were able to enjoy it. Some others got off looking a bit sorry for themselves.