Some time ago, I promised technomist that I would post a photo of the model boat my son designed and we both made. That was back in this post [here].
Well, here is the photo.
The boat is a rather unusual, paddlewheel trimaran made from plywood and two empty juice bottles. The paddles are driven by an electric motor from a now defunct RC car. We do need to do a bit more work. The paddlewheels need to be enclosed because they kick up lots of water which gets into the hull and upsets the electrics. 
In some later posts, I'll describe the model boat I'm building.
sleeper
By the way: we took this to a model boat show and it was greatly admired by everyone. A good 1st boat for a 9 year old.