Wave Energy Extraction Device

A wave energy extraction device comprises a plurality of generally vertically extending plate assemblies (9a, 9b, 9c), each plate assembly being mounted on respective generally upright arms 7', the lower ends of which are pivotally attached to a basal frame (5a, 5b), about substantially parallel, horizontally spaced-apart pivotal axes (13). At least one energy absorber (17a; 36, 38'; 71, 72) has direct or indirect respective drive connections (19a, 19b; 61, 65) with the adjacent plate assemblies. The arrangement of the drive connections is such that relative displacement of the adjacent plate assemblies (9a, 9b; 9b, 9c) towards and/or away from each other, as accommodated by pivotal movements of one or both plate assemblies relative to the basal frame about the pivotal axes (13), results in operation of the energy absorber. The distance between a first and second plate assembly (9a, 9b) is desirably twice the distance between the second plate assembly (9b) and a third plate assembly. In one embodiment, FIG. 1, the energy absorber (17a) is mounted on top of a plate assembly (9b) and driven by a mechanical connection (19a), but in another embodiment, FIG. 5, the energy absorber (71, 72) is connected by hydraulic lines (61, 65) to hydraulic cylinders (55, 56) connected to the plates.