When I was a teenager I built a pedal-powered canoe. It's made out of plywood without any curves, sealed by mastic in screwed-down joints, and has parts of a child's bike as the propulsion system. So its appearance is very Heath Robinson.
I never quite finished the project because I stopped spending time with a friend who had a lake. But I got to the stage where it was tested as keeping the water out. Then it was varnished and forgotten about. As I recall, the things that need finishing are securing the paddles to the shaft, adding a belt to transmit the power (pretty much anything would do here) and making a rudder to suit the bracket. So it's an almost-finished project that's about 15 years old, and has been stored under cover.
It seems a shame to junk it, so it's free to a good home. We're on the Shropshire-Staffordshire border. Anyone got a teenage son who might enjoy it? This is a Dangerous Book for Boys type of project, although it pre-dates the book by about a decade.
E-mail me (cdt22 AT cantab DOT net) if you want it or need more information.
PS: It's probably big enough for an adult too :-).