Marine Day is a public holiday in Japan, held on the third Monday of July. It celebrates the ocean’s bounty and Japan’s identity as a maritime nation, with families flocking to beaches and aquariums across the country.
- Held on the third Monday of July each year
- Families flock to beaches for swimming and water sports
- National aquariums host special events
- Commemorates the Meiji Emperor’s 1876 voyage
- Known in Japanese as Umi no Hi (海の日)
What it is
Marine Day, known in Japanese as Umi no Hi, is a national holiday dedicated to appreciating the ocean and reflecting on its vital role in Japan’s prosperity and daily life. As an island nation, Japan’s culture, economy, and traditions are deeply tied to the sea. On this day, people give thanks for the ocean’s resources and recognize the importance of maritime activities to the country’s well-being. The holiday also marks the arrival of summer, inviting families and friends to enjoy the coastlines and celebrate the connection between people and the sea.
Where it comes from
Marine Day traces its roots to Marine Memorial Day, first established in 1941 to commemorate the Meiji Emperor’s 1876 voyage aboard the Meiji Maru, an iron steamship. The emperor’s journey around the Tōhoku region and return to Yokohama on July 20 became a symbol of Japan’s maritime progress. However, Marine Day only became a national holiday in 1995, and it was first observed in 1996. In 2003, the date was shifted to the third Monday in July as part of the Happy Monday System, which aimed to create more three-day weekends for workers and families.
How it is celebrated
Celebration of Marine Day is relaxed and joyful, with many families heading to beaches such as Isshiki Beach in Hayama to swim, snorkel, surf, or dive. The holiday is a chance to enjoy the summer weather and the sea’s refreshing embrace. Some communities host unique activities like mud-ball throwing, while national aquariums across Japan put on special water-themed events for visitors of all ages. Whether by the shore or at an aquarium, people take time to reflect on the ocean’s gifts, enjoy seafood, and spend time with loved ones, making the most of the long summer day.
Joining in
If you visit Japan during Marine Day, expect lively beaches and a festive, summery mood in coastal towns. Popular spots like Isshiki Beach in Hayama draw crowds eager to swim and play in the sea. Aquariums often feature special programs and exhibitions. As a visitor, you can join locals in beach activities, sample fresh seafood, or simply relax by the water, soaking in the atmosphere of gratitude and celebration that defines this national holiday.
Sources and attribution
This page is Mela's own summary, written in new words. Its facts are drawn from the Wikipedia article Marine Day, whose text is available under the CC BY-SA 4.0 licence, and from its Wikidata record (CC0). Each photo is credited to its author beside it. For the full account, read the originals below.
Read more
This page was written with AI assistance from the sources listed above, and checked automatically before publishing. Spotted a mistake? Tell us. Last refreshed 2026-10-02.
Cultural
Spiritual
Spiritual
Sports
National days
National days
National days
National days