Diving in Honshu

Honshu is the largest, most populated island of Japan and is regarded as the Japanese mainland. Most of Japan’s early history took place in its southern region. Also, with the metropolitan areas of Tokyo, Yokohama, Osaka, and Kobe, it is Japan’s economic center. Honshu is also home to Japan’s highest mountain, Mount Fuji, and its largest lake, Lake Biwa. Honshu has an area of 87,992 square miles (227,898 square km) and contains almost three-fourths of the total number of prefectures of Japan. The coastline extends 6,266 miles (10,084 km). Along this extensive coastline divers will find temperate ocean conditions influenced by the Kuroshio Current that flows from the South China and Yellow Seas. Under these waters grow amazing kelp forests that are home to a mix of warm and cold-water marine life. Diving in Honshu offers a variety of sites be it ocean, river, or lake. Popular dives include the Ito Shark Scramble where hundreds of banded hound sharks, stingrays, and groupers swarm helmeted divers, swimming with dolphins in Mikurajima, and encountering whales in Ogasawara. A large number of macro species, especially nudibranchs, are also found in Honshu, making this region home to some of the best diving in Japan.

Featured places to go in Honshu


Plankton abounds where the cold and warm currents collide in the waters off Tohoku, making it one of the best fishing grounds in Japan.

Learn more

Boso Peninsula

Boso Peninsula is famous for its long, eastern sandy beaches, great waves, and easy access from Tokyo, also aoffering excellent diving.

Learn more

Shonan and Miura Peninsula

Shonan and Miura Peninsula offers divers a uniquely striped terrain that has formed from the accumulation of sand and rocks over time.

Learn more

Odawara and Manazuru Peninsula

In Odawara and Manazuru, there are many reefs and sandy areas off the coast to explore.

Learn more

Izu Peninsula

With a wide variety of diving including caves and wrecks, the Izu Peninsula offers some of the most popular sites and best diving in Japan.

Learn more

Chubu lies between two major diving areas, the Izu and Kii Peninsulas and offers several great inland dive sites to explore.

Learn more

Izu Islands and Ogasawara Islands

the Izu and Ogasawara Islands are as beautiful topside as they are underwater and offer dives with sea turtles and hammerhead sharks.

Learn more

Aquatic Life in Honshu

Honshu is home to many large cold-water marine species such as the Nomura’s jellyfish, one of the largest jellyfish species in the world, the giant Pacific octopus, and the gentle, wild dolphins of Noto Peninsula, one of only four locations where you can swim with dolphins in Japan. Other amazing Japanese marine life encounters in Honshu include the large Asian sheepshead wrasse, the yellow-spotted bandfish, and hordes of hammerhead sharks found congregating in the summer just off Mikomoto Island. Want to go shark diving in Japan? Visit Tobishima May to early July when hundreds of docile banded hound sharks gather to spawn inside the cave.

Dive Sites in Honshu