I stopped in at a local outdoor shop and looked at some of the new hobie cat kayaks. They have a foot pedal propulsion system that is a new gizmo to me.

A system of gears and pulleys transfers a back and forth pedal motion into two fin shaped occilating blades mounted below the hull. The whole system is about 20" long and mounted through a hole in the deck, it could be removed and replaced with a plug or mast step as desired. It was a slick little piece of engineering.

Is anyone familiar with this system? How much thrust can it develop compared to a standard paddle? The fin surface area and range of motion seemed awfully small compared to a regular paddle blade.