This sounds like a great idea to me.
There are sites like "Quirky" in which you can post an idea like this. When you submit the idea it creates a community wide brainstorm. You, and other people, can submit ideas for how it would work. If there are enough votes, or the company decides it seems like a good idea, they make it a reality. Pretty cool way to do it and get paid, if you don't want (or can't) to do all the work yourself. Give us a link and I'll check it out too. (By the way, I'd add a GPS tracker to the device idea. Then, it not only floats, but you can track it with a smart phone.)
Isn't quirky kinda dead? I liked the idea, but we need a Quirky that is truly of for and by the people, and also, they didn't get too many good or great ideas there years ago when I last looked.
That's probably exactly halfway down my list of "ideas" that I'm planning to publish in a children's book, the core of which, is "A Story", that goes viral, and ends up actually "Being The Thing", which finally facilitates egalitarian "City-Zen Sourcing" [say "CryptoQuirk"], and changes EVERYTHING. Thanks though. I do think it could work. If only more people could afford boats lol