We went for the half-day experience canoeing down the Wekiva river. You don't often find tours that offer a choice between a kayak and a canoe, so as soon as we saw this tour, we decided to go.
It was a fantastic trip! The river doesn't get a lot of boat traffic, so for the most part of the trip we only had to share the river with the wildlife. We saw countless birds and several alligators, two very young ones and one "teenager", as our guide called it :-) Our guide was very knowledgeable and offered a running commentary of everything interesting we saw.
The only downside of our adventure was the Florida weather - it was nice and sunny all time except for 10 minutes of a crazy downpour in the middle of the trip, so we spent the last 2 hours soaking wet. Well, I guess we did ask for a proper Florida experience :-)