The BlueNav Bluespin electric propulsion system is a clever invention that for now will help us transition from the ICE age to the Electric Age which is probably a decade or so away. We discovered it at the METS Trade show in Amsterdam last November. It essentially creates an easy-to-retrofit hybrid system, but the inventor points out it is also ideal for new boat builders to incorporate in their boats at low cost.
The unit consists of a retractable electric motor that lets a captain switch from fossil fuel to electric propulsion at the touch of a button. The shaftless, gearless motor is housed in the ring, with the rotor sitting within the surrounding stator that is also ring-shaped and creates prodigious torque. Since the blades are mounted to the rotor ring, there are no tip vortices to make noise and create drag. Watch the video and see the invention working.