While the Japanese economy remains stagnant, leisure activities are attracting attention in the pursuit of a diverse and rich lifestyle, one of which is the leisure use of the sea. Although many people want to visit the sea, the number of people participating in marine leisure activities is on the decline. This is due in part to factors such as the diversification of leisure activities, but it may also be that the providers of opportunities are not responding to the existing needs for leisure use of the sea. In order to realize the contribution of leisure uses of the sea to a richer life, it is necessary to appropriately combine measures to expand needs and measures to respond to potential needs.

As marine leisure use has increased, conflicts between the fishing industry and marine leisure have arisen in various places over the use of the sea surface, but in recent years, conflicts have been overcome and harmony, coexistence, and mutual prosperity have been achieved. In the absence of laws regulating marine leisure, systems to prevent trouble and accidents before they occur are being created in various places according to the local situation.

Looking into the history of "sea bathing," it is possible to deduce from various theories that it was introduced from the West from some time in the late Edo period to the early Meiji period for the purpose of treating illnesses and recuperating. In this paper, I would like to discuss the history of "sea bathing" that was introduced through Western medical awareness and the history of "sea bathing" that was practiced by foreigners who came to Japan.