This chapter describes the experimental results from the operation of a prototype green ship in Geoje island, South Korea. As Korea is a peninsula situated between the continent and the sea, its location is ideal for utilizing a photovoltaic (PV)/diesel green ship. The prototype green ship consisted of a PV generation system, a diesel engine, battery energy storage, a hybrid control system, and a stand-alone and grid-connected inverter. PV is the primary power source of the system for the electrical loads in the ship, and the diesel engines are used to compensate for the fluctuating electric power from the PV system. The chapter discusses the hybrid system configuration and operation mode. It provides an environmental, economic, and sensitivity analysis of the hybrid green ship. The operation of the hybrid PV/diesel green ship is divided mainly into modes A and B.