Helicopter? Close, but not quite, since the rotor blades are fixed-pitch. We’ll just go with “monocopter” for now and sort out the details later for this ducted-fan, thrust-vectored UAV.

This can be used for propulsion on a boat, by spinning a tall cylinder called a Flettner rotor. This takes advantage of Magnus effect to generate thrust. The boat uses a 3D-printed hull ...