Every summer, Japan celebrates Marine Day (海の日 – Umi no Hi) – a national holiday dedicated to the ocean and the deep respect the Japanese people have for it. Observed on the third Monday of July, Marine Day marks both the blessings of the sea and Japan’s maritime heritage.
In 2025, Marine Day falls on July 21, kicking off a long weekend that signals the heart of summer.
Why Marine Day Matters
As an island nation with over 29,000 kilometers of coastline, Japan’s history, economy, and way of life have always been tied to the ocean. From ancient sea trade routes to modern-day fishing industries and maritime technology, the sea has shaped the rhythm of Japanese life.
Marine Day is not just a holiday – it’s a reflection of gratitude. The day is meant to give thanks for the ocean’s bounty and recognize the importance of Japan’s maritime development and ocean conservation.
Utagawa Hiroshige – Ocean off Satta (1858)
How Japan Celebrates Marine Day
Marine Day isn’t marked by one large festival, but rather by regional seaside events across the country. These often include:
- Beach festivals and fireworks
- Maritime exhibitions and sailing parades
- Cleanup events to preserve coastal areas
- Family trips to aquariums or coastal towns
- Special cultural and environmental awareness campaigns
In Tokyo, places like Odaiba, Yokohama Bay, or Enoshima hold waterfront events. Meanwhile, coastal regions in Okinawa, Hokkaido, and the Seto Inland Sea offer their own local versions of the celebration, from ocean sports to seafood tastings.
What It Means Today
In today’s Japan, Marine Day is a gentle reminder that the sea is more than scenery—it is a lifeline, a protector, and a cultural cornerstone. As climate awareness grows, the holiday also reflects Japan’s commitment to ocean sustainability and environmental education.
Over 90% of people live near the sea
Whether you’re enjoying the coastline, learning about marine science, or simply soaking in the ocean breeze, Marine Day is a time to connect with Japan’s most powerful natural element.
This July, celebrate the sea – because in Japan, the ocean isn’t just part of the view. It’s part of the soul.