The student in recent years has the experience of a superficial sea in the secondary natural environment that is modified artificially and managed. However, it seemed that they were not experiencing the experience of the sea that nature originally had every year. As for two experience activities, the execution time and the period that differs the content of execution are also different. It was a little to consider the existence of the sea though they lived in the island nation it was possible to say by common in these two experience activities, and relations with the sea were also few, and the practical experience was uniformity (leisure like sea bathing etc.) and extremely scarce. It knew the sea was to tell the truth very familiar in them by experiencing the practical study, and it came to consider various respects of the environment of the sea strongly in addition. Especially, it was enumerated that high school students came to think how to do this sea toward the future by them.