Listen to the employees about paddling efficiently, and conserve some energy for the last 20 minutes - the river widens and the current slows; you'll have to work at it a bit to finish.
I went through 3 liters of water. I probably should have gone through all 4 that I had.
It's really nice in the morning. As the day goes on, if you start getting hot, put your hat in the water and put it back on your head. It helped a lot my first trip, and I should have done it my second.
Oh, yes - you'll want a hat. And sunblock you can reach easily.
We've been twice, and because of varying rainfall, dam releases, and such, it was like two entirely different rivers. When you get away from the tubers and it gets quiet, you'll see the wildlife - waterfowl, raptors, roadrunners, deer, and the horses, who will probably be in the river with you.