We've written plenty about these guys over the years. Operating out of Linz, Austria, CycloTech exists to propagate and commercialize a single idea: the CycloRotor propulsion system.

In the marine world, they're known as Voith-Schneider propellers, and these spinning barrels of thrust have "walls" made of wing blades, designed to tilt as the barrel spins thanks to conrods connected to a swashplate. This arrangement works a lot like the way helicopter rotors work – causing the blades to continuously vary their pitch as the barrel rotates, so that thrust peaks at a certain point in the rotation and quickly dies back down.

This arrangement means that you can run the barrels around at a more or less constant motor speed, and then direct thrust nearly instantly in 360 degrees – mainly downward, in this application, but it's just as easy for these barrels to fire thrust rearward, to accelerate you forward; forward, to effectively hit the air brakes; or even upward, if gravity's not going to accelerate you quickly enough toward the ground.