A wave energy electric power generation system has a buoyant body responsive to wave movement and an associated, relatively vertically stationary body, a compressor, a pressure regulator, and an air turbine/generator set. The compressor has a piston that moves reciprocally relative to a cylinder to alternately compress air in opposed chambers. A pressure regulator tank defines a chamber in communication with the compressor for alternately receiving compressed air from opposed compression chambers, a floating piston within the tank applying pressure to compressed air in the chamber, a pressureregulator controlling pressure applied by the piston to the compressed air, and an hydraulic dampening system coupled to the floating piston to restrict unwanted vertical oscillations of the piston, for output of a continuous flow of compressed air at relatively constant pressure. Rolling diaphragm and liquid trough sealing between opposed regions of contrasting pressure/vacuum are also described.