Mike Waters describes the Vril propulsion system, based on the Repulsine implosion drive created by Viktor Schauberger. Waters believes that these systems relied on inertial propulsion to produce reactionless thrust that would have allowed the Vril to function in space.
According to Waters, based on photographic evidence of the Vril, intake and outlet nozzles are evident on Vril 1 & 2, but not on Vril 3. He believes that this generation of the craft had evolved from using a Coanda-effect tornado above the craft to produce lift to being a fully self-contained inertial drive based on liquid mercury.
This video is compiled from excerpts from a larger discussion of inertial propulsion technology taped by American Antigravity with Waters at TeslaTech 2006.