US 7,541,688 B2
	Floating apparatus for deploying in marine current for gaining energy
Graeme Charles Mackie, North Shelds (United Kingdom)
Assigned to Ocean Flow Energy Limited, North Shields, Tyne & Wear (United Kingdom)
Appl. No. 11/667,902 PCT Filed Nov. 17, 2005, PCT No. PCT/GB2005/004432 § 371(c)(1), (2), (4) Date May 16, 2007, PCT Pub. No. WO2006/054084, PCT Pub. Date May 26, 2006.
Claims priority of application No. 0425303.5 (GB), filed on Nov. 17, 2004.
Prior Publication US 2008/0050993 A1, Feb. 28, 2008
Int. Cl. F03B 13/00 (2006.01)

U.S. Cl. 290—54

32 Claims

1. A device for extracting the kinetic energy from a tidal stream or ocean current the device comprising: a buoyant semi-submerged structure having low motion characteristics moorable by a non-rigid mooring system, the buoyant structure supporting at least one substantially horizontal axis rotor, which in use is submerged, wherein the buoyant structure comprises at least one body, and at least one substantially vertical surface-piercing strut of small waterplane area attached to the body, wherein the at least one body provides the greater portion of the buoyancy of the structure and wherein the combined buoyancy of the at least one body and the at least one substantially vertical strut is sufficient to support the total weight of the device in water plus the vertical component of load of the mooring while maintaining a certain freeboard of strut above the design waterline providing reserve buoyancy.