A wave energy converter comprising: a float (1.1) intended to lie along the surface of a body of water and designed to move in-phase with the waves present in the body of water; a spar-like element (1.10) intended to float in the body of water, the spar like element tending to move up and down in a vertical direction in response to passing waves, generally out of phase relative to the waves; impeding means (1.7) attached to the spar like element for increasing the effective mass of the spar for stabilizing the spar, impeding its up/down motion, while still allowing it to move, and causing it to drift down in still water; a cylinder (1.5) attached to the upper end of the spar like element for moving in tandem with the component to which it is attached, said cylinder enabling air to be compressed, said cylinder being generally enclosed with at least one inlet port (1.11) for allowing atmospheric air to be drawn into the cylinder and at least one outlet port (1.6) for outputting compressed air; and a piston (1.2) within the cylinder rigidly connected via a piston rod (1.3) to the float whereby the piston compresses air within the cylinder as a function of the movement of the float relative to the spar-like element; wherein the inner portion of the cylinder (1.5) above the piston (1.2) is defined as an upper chamber (1.8) and wherein the inner portion of the cylinder below the piston is defined as a lower chamber (1.9); characterised in that the steady state position of the cylinder relative to the piston changes as a function of the drift down movement of the spar in a direction to decrease the volume of one of the two chambers while increasing the volume of the other chamber for enabling the compression stroke of the piston to be automatically regulated. a float (1.1) intended to lie along the surface of a body of water and designed to move in-phase with the waves present in the body of water; a spar-like element (1.10) intended to float in the body of water, the spar like element tending to move up and down in a vertical direction in response to passing waves, generally out of phase relative to the waves; impeding means (1.7) attached to the spar like element for increasing the effective mass of the spar for stabilizing the spar, impeding its up/down motion, while still allowing it to move, and causing it to drift down in still water; a cylinder (1.5) attached to the upper end of the spar like element for moving in tandem with the component to which it is attached, said cylinder enabling air to be compressed, said cylinder being generally enclosed with at least one inlet port (1.11) for allowing atmospheric air to be drawn into the cylinder and at least one outlet port (1.6) for outputting compressed air; and a piston (1.2) within the cylinder rigidly connected via a piston rod (1.3) to the float whereby the piston compresses air within the cylinder as a function of the movement of the float relative to the spar-like element; wherein the inner portion of the cylinder (1.5) above the piston (1.2) is defined as an upper chamber (1.8) and wherein the inner portion of the cylinder below the piston is defined as a lower chamber (1.9); characterised in that the steady state position of the cylinder relative to the piston changes as a function of the drift down movement of the spar in a direction to decrease the volume of one of the two chambers while increasing the volume of the other chamber for enabling the compression stroke of the piston to be automatically regulated.