The Japan Maritime Self-Defense Force held an official flag lowering ceremony for JS Udzushio, an Oyashio-class submarine, marking the end of 25 years of active duty in the Japanese fleet.
Udzushio officially entered service on March 9, 2000. Construction of the ship began on March 6, 1996 at Kawasaki Heavy Industries’ Kobe facility, and it was launched into the sea on October 15, 1998. The design is part of a generation that has played a central role in Japan’s undersea deterrence and surveillance capabilities over the past several decades.
As of December 2025, the Japanese Navy still operates six Oyashio-class submarines. Of these, two units—Isoshio and Makashio—have been converted for training functions and used in the formation of new crews.

Technical characteristics
The Oyashio class submarine has a standard displacement of 2,750 tonnes and a submerged displacement of around 5,500 tonnes. With a length of 82 meters and a width of 8.9 meters, this ship is capable of reaching up to 12 knots when sailing on the surface and around 20 knots when diving.
The standard crew consists of approximately 70 personnel. Armament includes six 533 mm torpedo tubes, compatible with Type 89 torpedoes and Harpoon anti-ship missiles.
Transition to a new generation

The direct successor to the Oyashio class is kelas Taigeiwhich is currently being built for the Japanese Navy. This new generation of submarines adopts significant improvements in acoustic footprint reduction and is equipped with a more modern propulsion system. To date, the Japanese Ministry of Defense has funded ten Taigei class units, with four units already in service and another four at various stages of development.
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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 image: MICHIYA MURATA X @MICHIYAM | Militarnyi. This content is created with the help of AI and reviewed by the editorial team.
