An underwater hydroelectric farm comprising a plurality of electrical generator assemblies arranged in an array on a bottom surface of a body of water within an ocean current path to take generate power from a kinetic energy caused by the flow of the underwater current. Each assembly is installed in a cradle, which is anchored with a pile driven system to the bottom surface. Each assembly is a modular system allowing for easy swapping out of an assembly under water. Generated power is transmitted to a land based facility directly to or through an intermediate transfer station. Generator portion may have internally or externally supported field windings. Various configurations of propellers may be used, some with channels or solid vanes and another being a spiral shaped propeller. All water exposed surfaces of the generator and propeller portions are coated with a non-conductive, heat dissipating, anti-fouling and water specific protective coating.