In thermoelectric generation applications, the two indispensable conditions are the hot source and the cold source to provide the temperature difference for the generator. Thus, the waste heat recovery from various high temperature gas or steam turbines on ships by thermoelectric generators (TEG) is promising because the ocean naturally plays a role as an infinitely large cold source. Among other options, a pilot study of the applicability of thermoelectric generation to the boiler section of marine power plants is presented through CFD (Computational Fluid Dynamics) modeling. It is found that more than 600 W power may be produced from the waste heat of a 300 kW boiler but without an obvious loss of the system safety.