In this report, the magnetically-coupled type resonator used in undersea WPT (Wireless Power Transfer) system was examined to become more practical systems. Many of AUV (Autonomous Underwater Vehicle) that target of this study has width about 1 m ~ 2 m. Therefore, in order to implement in it, we have confirmed the various characteristics in the case of using larger resonator than ever. Moreover, we have performed the study that placed salt water on one side of the resonator until now. However, to correspond actual various demands, we have confirmed the characteristics of the case of arranging the salt water on both sides of the resonator.