Umi no hi or as some call it Marine Day in Japan is celebrated on the 3rd Monday in July. This year it will be on July 17, 2017. This day hasn’t been nationally recognized holiday until 1996, before then it was known as “Marine Memorial Day” and was not considered a national holiday.
This day was set up in 1941 to mark the Anniversary of the return of the Meiji Emperor to the Port of Yokohama on the two-masted topsail schooner Meiji-Maru, from a tour of the Tohoku and Hokkaido regions, in 1876.
During this day the people express thanks to the sea for its bountiful gifts, to honour its importance and to pray for the prosperity of Japan being a maritime nation.
Since this is more of a modern holiday there are not special or particularly traditional ceremonies to be held. But for this holiday in celebration of Marine Day all the national aquariums will organize things such as special events, water sports competitions, water shows, and cultural activities relating to the sea can take place in which young and old are allowed to take part in if they wish.
A lot of people do take this opportunity to enjoy the first little marks of the summer holiday and head to the beach for fun activities.