Riding on "Big Bertha" (the giant inner tube in the picture) is some of the most fun I've had here.
Katie promptly doggy paddled back to the boat and refused to ride in the tube again.
I can tell you from experience, it's easy to climb in the tube when you are in shallow water.
It's nearly impossible when you are in way over your head and there is nothing to stand on.
But it is quite amusing to watch when you are safely riding in the boat and out of their reach.