Explore Shikoku

Shikoku offers a captivating diving experience that appeals to both beginner and seasoned divers. Situated in a region blessed with the warm waters of the Kuroshio Current, Shikoku allows diving enthusiasts to explore its marine wonders throughout the year. With numerous dive sites located less than a 15-minute boat ride away, the convenience of accessing these underwater treasures is unmatched. Beginners can also enjoy shore dives at shallow sites, making it an ideal destination for all skill levels. The region's diverse underwater terrain boasts exhilarating pinnacles, drop-offs, and arches, adding an element of adventure to each dive.

The biodiversity in Shikoku's waters is nothing short of spectacular. Thanks to the nutrient-rich currents, divers can encounter over 1,000 species, a fascinating blend of tropical and temperate marine life. Vibrant table corals are home to colorful tropical fish, creating a mesmerizing seascape. This rich marine diversity draws biologists and photographers eager to capture the region's unique underwater world. Known locally as the sacred place of Japanese macro creatures, Shikoku provides an extraordinary dive experience, surrounded by natural beauty and tranquility, away from the bustling crowds. Between dives, the island's enchanting landscapes, from Naruto’s natural whirlpools to its hidden waterfalls, offer endless exploration opportunities on land as well.

Dive Sites Show on map

SSI Service Center Japan, 101-0051 Chiyoda-ku

Kashiwajima Island (★3.9)

Kashiwa Island is an island less than 4 km in circumference at the southwest end of Shikoku, at the tip of the Otsuki Peninsula, which juts out to the south of the Bay of Shukumo. It is designated as a national park and is connected to the mainland of Shikoku by a bridge and is accessible by land.

Nishiumi-Kankousen, 7984205 Minamiuwa-gun

Kode no dokutsu (★0.0)

While this dive site may appear typical on the surface, beneath the water’s surface lies an underwater cave that extends for 25 meters in length and 10 meters in width. These caves are not particularly deep, allowing divers to move slowly and search for large rays and sharks that occasionally rest inside. The exit of the cave emits a blue glow, and the upper section of the cave teems with schools of lanternfish and other marine life, creating a stunning visual display when illuminated. For divers, this location holds a special allure as it offers the opportunity to explore caves and revel in the breathtaking underwater scenery.

Nishiumi-Kankousen, 7984205 Minamiuwa-gun

Koyoko Island (★4.4)

This dive site is among top 5 for its enchanting allure and beauty within the region. Here, you’ll marvel at the splendid coral colonies and vibrant schools of fish. After a safety stop, you can even venture into captivating underwater caves. While the current can occasionally become swifter, I often recommend diving during low tide. When entering the water from the boat, you’ll find a calm 5-meter depth, making it a fantastic spot suitable for beginners and providing a sense of security.

Nishiumi-Kankousen, 7984205 Minamiuwa-gun

Yokoshima danso (★4.8)

Like a fault line, there is a mix of hard and soft corals on the monolithic rock. The depth ranges from 5-9 m, and the colony extends over more than 1 km in a straight line, with side holes next to the monolith allowing swim-throughs in some areas. Hard and soft corals coexist, and this type of landscape is rare in Japan. Sometimes rays, which can grow to over 2 meters, can be found hiding in the side holes. The scenery in shallow areas where light shines through is extremely beautiful.

Nishiumi-Kankousen, 7984205 Minamiuwa-gun

South Rock (★3.9)

The southern slope of this area has been significantly eroded by powerful typhoon waves, resulting in dramatic cliffs that reach heights of 30 meters, offering a dynamic and visually striking landscape. As you navigate around the rocky formations, you’ll encounter steep drop-offs. Between depths of 25 to 35 meters, there are extensive terraces along the southern slope, making it an ideal location for enthusiasts of underwater ruins and unique topography. Occasionally, large fish also make appearances here, adding to the excitement, so keep a lookout for them.

Nishiumi-Kankousen, 7984205 Minamiuwa-gun

Yokoshima 2 gōchi (★4.2)

Swim the mid-water to the tip with the coral ridge on your right, and you may see a large school of Japanese horn sharks descending from above. Large stingrays and turtles live in the neighboring waters, so you may be lucky enough to see them. After waiting for the school at the tip, you will see a gentle slope with a carpet of soft corals, gradually getting shallower and shallower until you reach the 5-meter safety stop, where kibibinago (sand eel) and other fish hang out. After the safety stop, we cross the natural maze created by the ridge and return to the boat.

Nishiumi-Kankousen, 7984205 Minamiuwa-gun

Akahae (★3.3)

This dive site is characterized by clusters of both soft and hard corals at a depth of approximately 20 meters. Frogfish seek refuge within the crevices, and at times, schools of migratory fish make their way through. While a diverse range of fish gather in this area, the presence of strong currents often requires careful consideration of diving conditions. Although typhoons had previously caused significant damage to the hard corals, there are indications of recovery as of 2023, making this site all the more appealing to divers.

Nishiumi-Kankousen, 7984205 Minamiuwa-gun

1 Gochi Ohanabatake (★0.0)

This is the first site in the National Park Marine Protected Area, the “Flower Garden site #1“. It is a special dive site that is difficult to anchor and can be dived by drift diving; it is easy to dive safely in the shallow range of 5m-12m, but the current is often too fast, so choose the sea conditions and go there when it is not a problem.

Nishiumi-Kankousen, 7984205 Minamiuwa-gun

Senohama Reef (★5.0)

This is a point where more than 20 square iron boxes of 3m in length and width are sunk. The former Nishinoumi Town sunk many of these boxes a long time ago in order to provide a home for fish. The place is crowded with migratory fish and the boxes are falling down on the sandy bottom. You can often take the route of going around and coming back to see the fish, but if you like macro, you can stay here and find pikachu and other nudibranchs.

Nishiumi-Kankousen, 7984205 Minamiuwa-gun

Kurohae (★4.0)

National Park Special Protection Area, site 5, Black Fly. Because the currents are often fast, we often choose this point on days when the tide is not moving and the sea conditions are favorable. This is a special point with an overwhelmingly large number of fish, and across the rocks to the north is a hard coral colony and to the south is a large colony of soft corals and nannyo goatfish. This is a place where you can enjoy the condensed scenery of the ocean in this area at a single point.

Nishiumi-Kankousen, 7984205 Minamiuwa-gun

Kashima Coral Beach (★4.7)

At Coral Beach on the uninhabited island of "Deer Island," National Park Special Protection Area No. 7, the water suddenly deepens from shallow to deep at a 45-degree angle. A rich ecosystem has been built here, with coral and shallow bays scattered about that serve as shelter for small fish, and deeper areas in the immediate vicinity. In summer, schools of yellow croaker appear in this area at a high rate, and kampachi, horse mackerel, squid, and other fish congregate to prey on them.

Mares

Uguru Island (★4.0)

Uguru Island is the southernmost town in Shikoku, 23 kilometers off the coast of the city of Shukumo. Due to the Kuroshio Current, the visibility in this area is one of the highest in Japan, and on a good day, the visibility can be as high as 50 meters. With its dynamic terrain and coral habitat, you can see tropical fish all year round. There are both big fish spots and macro observation spots, and both beginners and experts can enjoy them.

Mares

Nishiumi (★3.9)

Nishiumi is located at the southwestern tip of Ehime Prefecture, on the border with Kochi Prefecture, and around the West Sea Peninsula, southwest of Aina Town. Boat diving is the main activity, but beach dives are also available.

Mares

Nyanko Rock (★4.0)

This dive site is just a two-minute boat ride from the West Sea, and it can also be reached by swimming in approximately 25 minutes. For those feeling adventurous, swimming to this site is an option, especially during the cooler months when catsharks are plentiful, and jawfish habitats are spread across the area. Typically, it serves as the first dive site due to its deeper average depth. It’s also well-suited for deep diving training, allowing divers to quickly descend to depths of up to 40 meters. Additionally, it’s an excellent choice for those interested in participating in a training course.

Aqualung

Akehama (★5.0)

Located in the western part of Ehime Prefecture, Akihama is a beautifully scenic sea with a rias-style coast and a fine white sandy beach of about 300m in length. You can enjoy a wide range of life forms, from macro to migratory and rooted large fish.

Diving in Shikoku

Shikoku, Japan, offers an array of compelling dive sites that attract both shore and liveaboard divers. Among the top destinations is the Muroto Anan Kaigan Quasi-National Park, where divers can explore vibrant coral gardens and encounter unique marine life such as the Japanese pygmy seahorse. Night dives here reveal fascinating nocturnal behaviors of local sea creatures, adding an adventurous edge to the diving experience.

For those interested in wreck dives, Cape Ashizuri presents intriguing opportunities with sites like the sunken cargo ship, which lies in accessible depths teeming with marine inhabitants. Shore divers appreciate the ease of entry and diverse ecosystems found around Shikoku’s coastline, while liveaboard options offer extended exploration of remote underwater wonders. This balance ensures a fulfilling experience for divers of all preferences and skill levels.

The best Months to dive in Shikoku

Shikoku offers diverse diving conditions throughout the year. In summer, water temperatures range from 22°C–28°C/72°F–82°F, providing warm and comfortable diving. Winter temperatures drop to 16°C–18°C/61°F–64°F, necessitating proper thermal protection. Visibility is generally good, often reaching 10–20 meters/33–66 feet, but can be affected by weather and tidal changes, especially during the rainy season.

Diving is possible year-round in Shikoku, though summer and autumn are particularly favorable due to calmer seas and better visibility. Winter diving requires more preparation due to colder waters. Typhoon season, typically from August to October, can bring strong winds and currents, potentially disrupting dive plans. Planning dives around these factors ensures a safer and more enjoyable experience.