A manually powered rowing vehicle is provided. A chain is wrapped around a
portion of first and second free-wheel wheel sprockets, which can spin
freely in one direction but not the other. The first free-wheel drive
sprocket drives a rear wheel. The second free-wheel drive sprocket
connects to one end of a lever arm, which pivotally connects to a frame.
When the rider pulls the other end of the lever arm towards their body,
the first free-wheel drive sprocket grabs the chain and pulls the chain
forward. The chain in turn pulls the second free-wheel drive sprocket,
which rotates the rear wheel forward. When the rider pushes the lever arm
away from their body, the first free-wheel drive sprocket spins freely to
allow the lever arm to return to the pull position without moving the
linked chain or the vehicle. Various embodiments for steering the vehicle
are also described.