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 began on 6 March 1996 at Kawasaki Heavy Industries’ facility in Kobe, and the vessel 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 in recent decades.
As of December 2025, the Japanese Navy still operates six Oyashio-class submarines. Among these, two units — Isoshio and Makashio — have been converted to training roles and are used in the training of new crews.
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Technical characteristics
Submarines of the Oyashio class have a standard displacement of 2,750 tons and a submerged displacement of about 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 standard crew consists of around 70 personnel. Armament includes six 533 mm torpedo tubes, compatible with Type 89 torpedoes and Harpoon sea-targeting missiles.
Transition to the next generation
The direct successor to the Oyashio class is Taigei-klassenwhich is currently being built for the Japanese Navy. These new submarines include significant improvements in acoustic signature reduction and are equipped with a more modern propulsion system. So far, Japan’s Ministry of Defense has financed ten units of the Taigei class, of which four have already entered the fleet and 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 has been prepared with the help of KI and reviewed by the editors.
