If you start at the farthest point from the car park then the ride down will take the best part of three hours anyway. There has always been a park warden near the exit point, they may have a word with you if you don't get out. As far as drinks are concerned, if you bring them in non-disposable containers they are allowed. They don't you bringing items that people would be tempted to just throw away.
The Ichetucknee flows into the Santa Fe river, so you may want to use a canoe or kayak. Usually we can bring water, and there are recycling bins for the bottles and cans.
Don't know if you're allowed to go further down river outside of park boundaries. No food or drinks are allowed. They have park rangers at the entrance of the trail checking your bags and if they find food or drinks they will not let you in until you get rid of them.
No alcohol. No disposable containers. Not sure they can stop you from continuing to float down river but you would have to find your way back to your car.
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