Through precision, high-accuracy sonar technology, our team has discovered the Kairyu, a special attack submarine used by the former Imperial Japanese Navy during World War II. The investigation involved underwater drone footage and diver-operated filming to examine the submarine in full detail. The Kairyu was found on the seafloor, and it is believed that it ran aground near Susaki while attempting to enter Shimoda Port after departing from Yokosuka, Kanagawa Prefecture, shortly before the war’s end.
According to data from the Japan Maritime Self-Defense Force, the Kairyu measures 17.28 meters in length and 1.39 meters in diameter, matching the dimensions derived from our sonar analysis.
Discovery of a Second Kairyu Submarine
In July 2021, six years after the first discovery, another survey was conducted in the same area. This time, a second Kairyu submarine was found just 650 meters southeast of the original site. Using high-precision sonar to map the seabed, the team pinpointed the exact location of the second submarine and successfully captured it on underwater drone footage.
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