This paper investigates an induction-heating (IH) system applied for heavy fuel oil (HFO) recovery system in the tank of sunken ship. For design of the system, the characteristics of load equivalent circuit parameters in case of varying the steel board square meters and gaps between steel board and working coil unit are studied. On the basis of these characteristics, the experiment of heating up heavy fuel oil in the tank under the low temperature has been tested. Through the experiment, the availability of the proposed system was verified. Finally, the design procedure of largescale working coil unit for induction heating and operation frequency is proposed.