The Japan Maritime Self-Defense Force conducted an official flag-lowering ceremony on the JS Udzushio, an Oyashio-class submarine, marking the end of 25 years of active service in the Japanese Navy.
Udzushio officially entered service on 9 March 2000. Construction of the vessel began on 6 March 1996 at the Kawasaki Heavy Industries shipyard in Kobe, and the submarine was launched on 15 October 1998. The design belongs to a generation that has played a central role in Japan’s underwater deterrence and surveillance capabilities over the past decades.
As of December 2025, the Japanese Navy still operates six Oyashio-class submarines. Among these, two units — Isoshio and Makashio — have been converted for training purposes and are being used to train new crews.
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Technical characteristics
Oyashio-class submarines have a standard displacement of 2,750 tons and a submerged displacement of approximately 5,500 tons. With a length of 82 meters and a width of 8.9 meters, they can achieve speeds of up to 12 knots in surface sailing and around 20 knots under water.
The normal crew consists of about 70 people. Armament includes six 533 mm torpedo tubes, compatible with Type 89 torpedoes and Harpoon anti-ship missiles.
Transition to the next generation
The direct replacement for the Oyashio class is Taigei-klassenwhich is currently under construction for the Japanese Navy. These new submarines incorporate significant improvements in acoustic signature reduction and are equipped with a more modern propulsion system. To date, Japan’s Ministry of Defense has funded ten units of the Taigei class, four of which have already been deployed in the fleet, while another four are in various stages of construction.
Thank you for your hard work for a long time to return the Self-Defense Flag. 😍 pic.twitter.com/cwyx3cVxkR
— MICHIYA MURATA (@MICHIYAM) December 19, 2025
Source and Images: MICHIYA MURATA X @MICHIYAM | Militarnyi. This content is created with the help of AI and reviewed by the editors.
