This is a bit further development of the pedal drive idea suited to the Cruiser 60 with a cockpit or deck well.
The drive units could be belt or chain driven with selected ratio. That is considerably lower cost than the gearboxes. They could drop through a reinforced hole in the well and locked in place. The lever arm that carries the seat could fold back onto the drive leg once removed to make stowage a bit easier.
To go in the opposite direction the unit would be lifted out and turned 180 degrees with the lever arm that supports the seat resting on a pedestal having the same height as the deck or alternatively supported in a bracket on the side of the cabin.
They could be placed with much less longitudinal separation as there is little interference from one prop to the other.