By using the training ship Seisuimaru, we observed of detailed oceanic condition in the vicinity of Cape Shionomisaki, the tip of the Kii Peninsula in April, 2009 and in October, 2009. The sea level difference between Kushimoto and Uragami tide stations is used to monitor the flowing path of the Kuroshio, or to identify whether the Kuroshio is taking the straight path or the meandering path. It is shown that this sea level difference occurs in the narrow region of 4-5 km off Cape Shionomisaki, and that the sea level difference is mainly created by the oceanic condition in the thin surface layer above 150m. This indicates that the structure of the Kuroshio does not influence directly to the sea level difference between Kushimoto and Uragami. The sea level difference indicates whether warm and light Kuroshio Water is brought into shelf region to the west of Cape Shionomisaki or not, and whether the sea level difference between coastal waters to the west and to the east of Cape Shionomisaki.