Because

1. My whitewater boat is a little bit tricky to paddle in a straight line... if you don't tow her, she may very well just spin in circles all the way down the river
When I want to work on my steering strokes, I take that boat out on flat water until I can get it to paddle straight.

2. As the statue of liberty, she has to be holding a torch. If she's holding a torch, she can't paddle


However, in retrospect, the idea of Zen spinning in circles all the way through the float is amusing enough. You guys can just make foam torches and strap them to either end of my paddle and she can spin in circles down the river with her paddle torch and you totally have to take a video of that for me.