- Japan’s Ministry of Defense confirmed that the Russian Navy corvette Gremyashchiy (337) transited eastward through the Tsugaru Strait on Feb. 1 and continued into the Pacific Ocean.
- The Japan Maritime Self-Defense Force monitored the transit using the escort ship Chikuma and a P-3C patrol aircraft as part of routine surveillance of foreign naval movements.
Japan’s Ministry of Defense confirmed that a Russian Navy Steregushchiy III–class corvette, identified as Gremyashchiy (hull number 337), transited eastward through the Tsugaru Strait on Sunday and proceeded into the Pacific Ocean, according to an official release from the Joint Staff.
The ministry said the vessel was first detected around 8:00 a.m. local time approximately 130 kilometers west of Tappi Cape in Aomori Prefecture, moving southeast before entering the strait that separates Japan’s Honshu and Hokkaido islands. The Tsugaru Strait is an international waterway routinely monitored by Japan’s Self-Defense Forces due to its strategic location connecting the Sea of Japan with the Pacific.
According to the Joint Staff, the Japan Maritime Self-Defense Force (JMSDF) conducted surveillance and intelligence collection using the escort ship Chikuma, assigned to the 15th Escort Division based in Ominato, along with a P-3C Orion maritime patrol aircraft from the 2nd Air Group at Hachinohe. The ministry said these assets tracked the Russian ship throughout its passage until it exited the strait and continued into the Pacific Ocean.
Gremyashchiy belongs to Project 20385, an improved variant of Russia’s Steregushchiy-class surface combatants. The class is designed for multi-role operations, including surface warfare, anti-submarine missions, and air defense. Ships of this type are typically armed with guided missiles and modern sensor suites, making them among the more capable corvette-sized platforms in the Russian Navy.
While the Japanese release did not specify the ship’s port of origin or intended destination, the transit marks another instance of Russian naval activity near the Japanese archipelago. Such movements are closely tracked by Tokyo as part of its routine maritime domain awareness mission.
The Ministry of Defense emphasized that the JMSDF response was limited to monitoring and information gathering, in line with standard procedures. Officials did not report any violations of Japanese territorial waters or airspace, noting that the transit occurred in international waters where freedom of navigation applies.
Maps and photographs released alongside the statement showed the ship’s track through the strait and a JMSDF image of the corvette at sea, providing visual confirmation of the vessel’s identity and movement.
Japan regularly publishes such notices when foreign military vessels pass through nearby sea lanes, particularly those used by the Russian and Chinese navies. The Tsugaru Strait, along with the Tsushima and Soya straits, is considered a key chokepoint for naval traffic between regional seas.
Russian naval movements around Japan have continued since the start of the war in Ukraine, with Moscow maintaining deployments in the Pacific and Far East. Japan, for its part, has expanded surveillance operations and public reporting to demonstrate transparency and readiness.