NOVELTY - A wave energy conversion device (1) includes a base (2) to be anchored to the bed (5) of a body of water and a generally rectangular flap (6) pivotally connected to the base and biased to the vertical. The flap includes an upper portion (8) upstanding above a pivot axis (7) to extract energy from wave motion and a lower portion (10) with a biasing mass located below the pivot axis. The mass provides a restoring force to bias the flap to the vertical when the flap oscillates back and forth. A power extraction unit draws out the power produced by the flap movement.    USE - Wave energy conversion device for use in relatively shallow water.    ADVANTAGE - The device can be more readily tuned to the wave periods existing in relatively shallow waters with depths of up to e.g. 20 meters, since the biasing mass provides a restoring force below the pivot axis of the flap. The location of the biasing mass below the pivot axis reduces the period of oscillation of the flap and enables the flap to exhibit larger angular movement and velocities when the period of oscillation is tuned to the period of wave motion, allowing the possibility of higher rate of power take-off. The base and the flap provide a continuous surface to the wave motion throughout the depth of the water, enabling the flap to capture maximum amount of energy from the wave motion prevailing at a given location. The weight provided by the biasing mass, as well as the mass of the rest of the flap and supporting structure, is made greater than the total vertical forces provided by the buoyancy of the flap upper portion, avoiding unnecessary vertical foundation forces. Additional weight or downward force acting on the base enables the base to be anchored to the bed of the body of water, reducing need for extensive foundations e.g. piles.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a method for extracting energy from waves.    DESCRIPTION OF DRAWING(S) - The drawing shows the perspective view of a wave energy conversion device.    Wave energy conversion device (1)    Base (2)    Bed (5)    Flap (6)    Pivot axis (7)    Upper portion (8)    Lower portion (10)