My SO and I are touring NZ, working on farms for room and board. Driving around I see all the touristy things, ferries, marinas etc. I had a brain wave and imagined a floating platform, like the bottom half of a boat, with dynamo rollers. You’d park your car atop it, strap the front wheels into cradles that would transfer your steering motion to the rear propeller, and your rear wheels would power the propeller via rollers. You could cruise the islands at your leisure!
You’d probably need stabilizing catamaran type floats to deal with wonky weight distribution, and a front wheel drive would be much more complex. I can also imagine some vehicles over heating from a lack of frontal wind speed. Anywho, now and again I dream up crap that comes into existence years later (like the musical road).
Does a car to boat conversion exist already?