Float the Santa Fe
Out of Gainesville, run up I-75 to exit 399, and head west on 441 towards High Springs. Once you get into High Springs, follow signs towards Ginnie Springs. Stop at a gas station along the way and grab a lot of beer and ice. Once you get to the springs, have them rent you an inflatable boat along with all your tubes, just throw the beer and ice in and float down the Santa Fe River for hours. Some people float Ichetucknee Springs, but it’s a state park, and they try pretty hard to keep alcohol out of the park. If you are looking to save some money and avoid the admission charge to Ginnie Springs, in High Springs you can continue on US-27 until Ft. White.
An old gas station on the corner will rent you tubes, and then you can haul them down State Road 47 (The other highway at that crossroads) until you cross the Santa Fe River at Hollingsworth Bluff. There is a little park at the bridge, and you can park a car there for when you finish. Then run a few more miles up the road until you see signs for Ginnie Springs, turn down that, and when that ends, take a left (instead of going right to get to the springs.) Follow that around about a ½ mile until it reaches the river, and put in there. That’s a good 3-4 hour float depending on how high the river is. It should be noted that this place has been fenced from time to time, and they’ve tried to get folks for trespassing. But it is a cheaper way to get on the river than going in at Ginnie Springs.