I used to work with a guy who wanted to build a raft for his quad so that he could ford a river during his upcoming hunting trip. He asked me to assist. He'd made a wooden 'box' just big enough for the quad to sit on, and get strapped down.
It was 8" thick. I tried to explain to him about "floatation" and how that works. His opinion was "this is good enough, I know what I'm doing, and are you going to help me or what?"
I then tried to explain to him the theory (Law) of displacement. His reply to that was, "I'm going to fill the box with extruded polystyrene insulation, so it'll be 'more floaty'."
It was about that point where I gave up, bit my tongue, and simply lended a hand to a co-worker.
He took his "USS Minnow" to a nearby river that weekend, to try it out. After the quad became an instant keel, he and a few others were able to locate and retrieve it all, by seeing this 'un-natural corner' poking out of the water, sporadically. Mostly whenever the handlebars and/or other luggage rack equipment was hitting a rock down below.
Oh, was he mad.
