Maybe I'm over thinking this but wouldn't a pontoon raft be safer and last longer?Withe price of palettes and plastic barrel you make one for about $500 and then just put a cheap tent on. To each their own tent for $100.
Had a friend who, in a drunken spree, constructed a pontoon raft out of palettes and plastic barrels. Sitting on that thing was the focal point of like 2 summers. Definitely recommend!
If you aren't going to move it then that probably is a much cheaper option, but moving a pontoon boat with either a trailer or disassembling it will take a lot more work than letting the air out of this floating tent.
In Asheville, the cool thing to do is to put a King-sized inflatable bed on the river and fall asleep with a mosquito net cover.