ABB's cycloidal marine propellers: Efficient thrust in any direction https://newatlas.com/marine/abb-dynafin-marine-propulsion/
ABB's cycloidal marine propellers: Efficient thrust in any direction https://newatlas.com/marine/abb-dynafin-marine-propulsion/
A shroud timed with the blade orientation would make this less terrifying possibly more efficient. Very cool.
