The Japan Maritime Self-Defense Force conducted an official flag-raising ceremony for the JS Udzushio, an Oyashio-class submarine, marking the end of 25 years of active service in the Japanese fleet.
The Udzushio officially entered service on March 9, 2000. Construction of the boat began on March 6, 1996 at the Kawasaki Heavy Industries shipyards in Kobe; the launch took place on October 15, 1998. The design belongs to a generation that has played a central role in Japan’s underwater deterrence and surveillance in recent decades.
As of December 2025, the Japanese Navy continues to operate six Oyashio-class submarines. Among them, two units — Isoshio and Makashio — have been converted for training roles and are being used to train new crews.
Technical features
Oyashio-class submarines have a standard displacement of 2,750 tons and a submerged displacement of around 5,500 tons. With a length of 82 meters and a width of 8.9 meters, they can reach up to 12 knots on the surface and around 20 knots submerged.
The standard crew consists of around 70 members. Armament includes six 533 mm torpedo tubes, compatible with Type 89 torpedoes and Harpoon anti-ship missiles.
Transition to the next generation
The direct successor to the Oyashio class is the Taigei-Klassewhich is currently being built for the Japanese Navy. These new submarines incorporate significant advances in acoustic signature reduction and feature a more advanced propulsion system. To date, the Japanese Ministry of Defense has funded ten Taigei-class units; four have already joined the fleet and another four are in various construction phases.
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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 was created with the support of AI and reviewed by the editorial team.
