That's exactly what I did yesterday.
Ged and I drove to Ichetucknee Springs just 45 minutes North of Gainesville to go "tubing," or, floating down a calm river on big plastic tubes.
We rented the tubes from an old man down the road for $5 each, drove into the park and set off on the trail leading us to the little launching dock.
It was probably the most relaxing thing I've done in a long time. From start to finish, we were in the river for an hour and a half.
There was no crowd, so we had the river pretty much to ourselves. The sun was warm but not too strong, the water was cool on our skin and the current was gentle.
I can't wait to go back.