Wave energy converter using an oscillating mass

Wave energy converters having a paddle form and facing the seas have been described in papers, previous designs having a sliding mass located low in the hull. Power is taken off by resisting the movement of the sliding mass. In this invention, the sliding mass is located high in the hull, generally above sea level, where it is more effective and so may have a substantially lower mass. In addition, instead of moving in a straight line, means may be provided for the slide to be curved in the vertical plane to improve performance. Further, the guiding means may be a pivoted arm or a linkage, rather than a slide, and the path may be variable to suit the period of the waves.