The present invention includes a means to sustain a rocket torpedo's supercavation envelope to enhance the speed, maneuverability and resistance to percussion based counter measures. The invention includes machines using those aspects of the invention. The invention may also be used to upgrade, repair, or retrofit existing machines, using methods and components known in the art. The present invention comprises a porous plate technique never associated with torpedo design. This approach differs from previous efforts to apply porous plate designs to surface ships and differs as a proportional gas flow is achieved to sustain supercavation during all aspects of a torpedo travel to include but not limited cruising, diving, surfacing and while executing turns of any turning radius.