© iStock/yongyuan 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 © MaresTohokuPlankton 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 © MaresBoso PeninsulaBoso Peninsula is famous for its long, eastern sandy beaches, great waves, and easy access from Tokyo, also aoffering excellent diving.Learn more © ScubaproShonan and Miura PeninsulaShonan and Miura Peninsula offers divers a uniquely striped terrain that has formed from the accumulation of sand and rocks over time.Learn more © MaresOdawara and Manazuru PeninsulaIn Odawara and Manazuru, there are many reefs and sandy areas off the coast to explore.Learn more © MaresIzu PeninsulaWith 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 © MaresChubuChubu lies between two major diving areas, the Izu and Kii Peninsulas and offers several great inland dive sites to explore.Learn more © ScubaproIzu Islands and Ogasawara Islandsthe Izu and Ogasawara Islands are as beautiful topside as they are underwater and offer dives with sea turtles and hammerhead sharks.Learn more Dive Sites in Honshu Discover the Wonders of the Deep with SSI's Blog Join us on an exciting journey of discovery and learn more about exhilarating diving adventures, dedicated conservation initiatives, and innovative educational opportunities that will help you illuminate the extraordinary beauty of the underwater world. Let's explore the underwater world together and delve into the hidden wonders beneath the gentle waves. The descriptions provided here are intended as general information and personal experiences related to specific dive sites and locations and should not be construed as definitive advice or recommendations. Before diving, please confirm that diving is permitted at your chosen location, and comply with all relevant local laws, regulations, and posted signage. The responsibility for verifying the legality of the dive and assessing any associated risks rests entirely with you.