Longest Sea Cave Discovered By Divers in Okinawa, Japan

Divers have discovered what could be considered the largest undersea limestone cave in Okinawa, a prefecture of Japan.

It has been confirmed that the main cavern and its branches have a total length of approximately 640 meters, which surpasses the 487-meter long Hidenchigama cave off Kumejima island in Japan.

Divers plan to further explore the newly discovered cave to prove their theory that the cave has a combined length of more than a kilometer.

Residents of Onnason, a coastal community on the Japanese Island, plan to set up a council to discuss how to preserve the cave while also using it as a tourist attraction.

Diver Toshiaki Hirobe, 38, who owns the Marine Dream diving shop in Onnason on the Okinawan Island, found the entrance of the cave 28 meters under the sea 1.5 kilometers east of Manzamo in April 1998.

In the summer of 2002, Hirobe and four other divers conducted more than 70 exploration dives into the cave.

Hirobe has stated that the cave entrance, which is only 50 centimeters high and one meter long, is only large enough for one person equipped with an oxygen cylinder to pass through the opening at a time.

Okinawa is south of the main islands of Japan, and is a two and a half hour flight from Tokyo. It is Japan’s most popular diving destination.