As part of a student competition, designers I. Kiryakov, S. Ballmeier, K. Eichelberg & M. Dressler have attached an exercise machine to a high-speed canoe hull, and called it the Tu-Fin. The vehicle transfers the movement of the stepping user to forward motion using a flipper, according to Treehugger
. What benefit does this offer to the more standard rowing that would take place in a normal canoe or kayak? None really, unless you are in need of leg exercise as opposed to arm exercise. Whatever your goal, it is pretty cool and vehicles powered by human strength always get a thumbs-up from us.