AbstractThis paper investigates the use of a controlled tethered wing, or kite, for naval transportation. Linked to a boat by light composite-fibre cables, the kite is able to fly between 200 m and 600 m above the sea and to generate high traction forces. A mechatronic system installed on the boat, named Kite Steering Unit (KSU), controls the kite and converts the cable speed and force into electricity. Differently from previous works, the boat is also equipped with two electric propellers, so that naval propulsion can be achieved both directly, through the towing forces exerted by the cables, and indirectly, through the electricity generated by the KSU and fed to the electric propellers via a battery pack. The results indicate that, by properly choosing the operating conditions of the system, a completely green naval transportation system can be obtained regardless of the wind direction.