A buoyant
actuator (19) for
coupling wave motion to a device operable in response to
wave motion in a body of water. The buoyant
actuator (19) comprises a generally
spherical body (20) defining an exterior surface and a hollow interior adapted to contain water received from the body of water. The exterior surface comprises a plurality of facets (101) which are tessellated. Typically, there are 36 facets (101), of which 12 comprise generally pentagonal facets (105) and 24 comprise generally hexagonal facets (107). The body (20) comprises a plurality of openings (143) for fluid flow between the hollow interior and the surrounding body of water. A closure configured as a flap (145) is provided for each opening (143) to block or at least inhibit fluid flow therethrough, the closure being adapted to move away from the opening to permit fluid flow therethrough in response to a predetermined
fluid pressure differential imposed thereon between the hollow interior and the surrounding body of water. The exterior surface of the body (20) is configured to viscously couple with water surrounding the body (20). The viscous
coupling between the surrounding water and the exterior surface of the body (20) provides added effective
mass to the buoyant
actuator (19) which is additional to the physical
mass of the buoyant actuator and the
mass of the volume of water contained in the body.