Abstract: A human-powered wheeled amphibious vehicle includes a substantially planar buoyant base member upon which the rider sits while pedaling to turn the rear wheels of the vehicle. The rear wheels have inner-tube-like pneumatic tires and blades and/or paddle structure for improved traction in water. A single front wheel is supported on the base member by a turntable which is oscillated by moving a pair of handles, each mounted in a slot in the base member and reciprocable fore and aft.