Abstract: 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.

Abstract: The invention, relates to means for absorbing, extracting or using for propulsion, wave energy occurring naturally in water. The invention overcomes existing breakwater devices of the type that were prone to puncture or were expensive to maintain, were inertial dependant or had mooring loads. One breakwater device comprises first and second structures, (100, 102) arranged substantially parallel one to another, said structures having neutral buoyancy and energy absorbers (111) mounted therebetween, whereby in use, the devices absorb energy from incident and waves as a result of relative motion between the structures. Preferably a third structure is positioned parallel to the second structure, there being a second energy absorber positioned between the second and third structures. Energy absorbers may be arranged to generate an electromotive force or pump a material or fluid. Advantageously a plurality of devices (206) can be interconnected, in the form of a chain or caterpillar to provide a breakwater system.