Located near the Izu Peninsula in Japan, Mikomoto Island (みこもとじま) is a pilgrimage site for divers worldwide, renowned for its spectacular schools of Hammerhead Sharks. Just three hours from Tokyo by car, this island draws divers from across the globe with its convenient location and rich marine life. Mikomoto offers not only heart-pounding dive experiences, but also carries the vision of local operators who hope to revitalize the community through tourism and attract young people to the diving industry.
Mikomoto: A Hammerhead Shark Paradise
At Mikomoto in Japan, there's a 70% chance of witnessing an overwhelming abundance of Hammerhead Sharks on any given dive. Photo courtesy of 京太郎
Makoto Arimatsu (有松 真), one of Mikomoto's local dive operators — whom we fondly call Arimatsu-san — shared with us that the undisputed highlight of Mikomoto Island is the Hammerhead Shark. Every year from June to October, the warm Kuroshio Current brings schools of Hammerhead Sharks, sometimes numbering in the hundreds, giving divers up to a 70% chance of witnessing this spectacle firsthand.
Compared to other Hammerhead Shark dive sites, which are often located in remote regions, Mikomoto's proximity to a major metropolitan area is truly rare on a global scale. The volcanic rock terrain surrounding the island, powerful currents, and diverse marine life — including mackerel, trevally, and colorful coral — add even more appeal to every dive.
However, strong currents and heavy swells make Mikomoto an advanced dive site. The local association requires divers to have a minimum of 50 logged dives and to be comfortable with drift diving. Because the waters are prone to strong currents, operators are mindful of the distance divers can drift from one another; to minimize risk, each dive is limited to 35 minutes to ensure everyone's safety.
Marine Conservation and Fisheries in Harmony
Arimatsu-san explained that, unlike some regions where sharks are caught for food or fishmeal, there is no tradition of shark fishing in the Mikomoto area, allowing Hammerhead Sharks to thrive freely here. Local dive operators work in partnership with four traditional fishing boat captains — some of whom have transitioned into dive tourism — to jointly establish diving regulations that protect the marine ecosystem and maintain sustainable tourism. This model, overseen by a local association, ensures that diving activities and fisheries coexist harmoniously, setting an example for other regions.
Overseas Experience Sparks Local Revitalization
The passionate Arimatsu-san (right). Photo courtesy of 京太郎
Arimatsu-san is acutely aware that Japan's diving industry broadly struggles with low wages and high turnover, making it difficult for many dive instructors to remain in the profession after starting a family. To address this, they have invested in upgrading facilities — for example, expanding their dive boat capacity from 24 to 40 passengers — and partnered with local inns and restaurants to create more employment opportunities.
These efforts aim to improve working conditions, attract young people to the diving industry, and bring economic vitality to the Shimoda area. In recent years, Arimatsu-san has also been actively participating in international dive expos, including ADEX and DRT, to welcome international dive guests. The operation currently accommodates visitors in both English and Japanese, and there are plans to recruit a Mandarin-speaking instructor to better serve Taiwanese and other Mandarin-speaking travelers.
Arimatsu-san (left) is a passionate advocate for Mikomoto at international dive expos such as ADEX and DRT.
Earlier in his career, Arimatsu-san worked as a diver in Australia, Thailand, and Palau, bringing back an international perspective and boundless enthusiasm. It is precisely this experience abroad that makes his team the only one among the four local dive operators willing to accommodate English-speaking divers.
They are dedicated not only to delivering world-class dive experiences, but also to driving economic development in the Shimoda area through tourism. Over the past decade, rising water temperatures and a closer-running Kuroshio Current have caused Hammerhead Shark numbers to surge, while online promotion has brought Mikomoto widespread recognition and attracted a large number of international divers. Currently, 70% of visitors come from overseas, with Taiwanese guests accounting for 30%.
Arimatsu-san hopes that dive tourism will transform the local industry and breathe new life into the community. Photo courtesy of 京太郎
Planning Your Diverse Mikomoto Adventure
Come and experience a travel vibe unlike anything you'd find in a big city. Photo courtesy of 京太郎
The best diving season at Mikomoto runs from June through the end of October, when water temperatures range from 21°C to 28°C and a 5mm wetsuit is sufficient. While Hammerhead Sharks can be spotted year-round, winter brings low temperatures and heavy swells that result in a 40% trip cancellation rate, making it inadvisable for international visitors to plan their trip during this period.
Unlike the dive environments of Southeast Asia, diving in Japan requires each person to assemble their own gear. This is primarily a straightforward way for operators to assess how familiar you are with your own equipment and whether you are ready to handle the challenges of an advanced dive site.
Beyond diving, visitors can enjoy the hot springs of the Shimoda area to which Mikomoto belongs, savor fresh seafood (such as eel over rice), or soak up the lively beach atmosphere during summer — especially in August — experiencing a relaxed travel vibe that stands in delightful contrast to the hustle of major cities like Tokyo and Osaka.
Where Adventure Meets Purpose
Mikomoto is not only a diving paradise — it is a living example of marine conservation and community revitalization. Photo courtesy of 京太郎
Mikomoto is not only a diving paradise — it is a living example of marine conservation and community revitalization. Arimatsu-san hopes that by promoting dive tourism, more people will come to appreciate the beauty of this ocean, while local young people gain access to a promising career path.
At present, only four registered vessels are permitted to offer diving services at Mikomoto, and Arimatsu-san's dive shop is the only one providing services in both Japanese and English (with Mandarin potentially available in the future). Because a Mikomoto Hammerhead Shark dive is extremely popular, it is highly recommended to book your trip at least six months — or even a full year — in advance.
Whether you are an experienced diver or an adventurer ready to take on an advanced dive site, Mikomoto will deliver an unforgettable journey that blends thrills, culture, and environmental purpose.
Start planning your Mikomoto dive trip today — dance with the Hammerhead Sharks and support the sustainable development of a local community!
Arimatsu-san
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