An open-ocean fish-growing platform has a submersible cage structure forgrowing fish, an antenna for receivingpositioning signals transmitted from an external source, a position-correctionapparatus for calculating a position error signal from atarget geostatic position, and an ocean thermal energy conversion (OTEC)system for generating electric power for thruster units tomaintain the cage structure in the target geostatic position. The OTEC systeminducts colder ocean water from a deeper ocean depthfor driving its heat exchange cycle, and is also of hybrid type using a fuel-fired unit as a heat source. The cold water effluent from theOTEC system is directed into the cage for flushing wastes generated by thegrowing fish. The self-positioning, self-powered open-oceanplatform enables unmanned, extended marine deployment in deeper ocean waterswithout the need for tethering or anchoringto the ocean floor.
