NOVELTY - An underwater power generator (10) comprises an underwater vessel (20) for navigating through a body of water (200) to transit through an underwater thermocline, electrically coupled thermo-to-electric energy converters, and a phase change material coupled to a surface of the thermo-to-electric energy converters. The thermo-to-electric energy converters comprise bismuth telluride or bismuth telluride-antimony telluride.    USE - Used in supplying power underwater (claimed), e.g. for military and civilian underwater vehicles.    ADVANTAGE - Power generation can be produced indefinitely by repeatedly transiting an underwater thermocline, thus presenting a virtually maintenance-free approach to underwater power generation as no moving parts are required.    DETAILED DESCRIPTION - An underwater power generator comprises an underwater vessel for navigating through a body of water to transit through an underwater thermocline having a temperature range, and including a shell; a portion of the shell of the underwater vessel made from a thermally conductive material, and having an outer surface in contact with the body of water and an inner surface opposing the outer surface and not in contact with the body of water; thermo-to-electric energy converters electrically coupled together and having a first surface thermally coupled to the inner surface of the portion of the shell; and a phase change material coupled to a second surface of the thermo-to-electric energy converters. The phase change material has a phase change temperature that is approximately equal to an average of upper and lower temperature extremes of the temperature range of the underwater thermocline, where the thermo-to-electric energy converters generate electrical power as the underwater vessel navigates through the body of water so that the underwater vessel transits through the underwater thermocline. The thermo-to-electric energy converters comprise bismuth telluride or bismuth telluride-antimony telluride. An INDEPENDENT CLAIM is included for a method for generating power underwater.    DESCRIPTION OF DRAWING(S) - The figure shows the underwater vessel transiting an underwater thermocline.    Underwater power generator (10)    Underwater vessel (20)    Body of water (200)    Surface of body of water (202)    Bottom of body of water (204)