A method for forming and imploding cavities within a cavitation chamber is provided. The method uses a cavitation piston, coupled to a hydraulically actuated piston, to form the desired cavities during piston retraction and then implode the cavities during piston extension. The cavitation fluid is degassed prior to hydraulically driving cavitation within the chamber. Degassing can be performed within the cavitation chamber or within a separate degassing chamber. In one aspect, a coupling sleeve is interposed between the hydraulic driver and the cavitation chamber. Preferably the coupling sleeve is evacuated. In another aspect, a cavitation fluid circulatory system is coupled to the cavitation chamber. In-line valves on the chamber inlets allow the chamber to be isolated, when desired, from the circulatory system.