Note: The following text was originally posted on my X/Twitter account.
Chinese and Russian diesel-electric submarines are reported to have undertaken a (joint) "underwater patrol" for the first time. It is important to note that the scope of China-Russia military exercises is not public knowledge, and it is possible that these much-hyped events primarily amount to navigational exercises that are intended to allow the Chinese and Russian militaries to safely operate alongside one another at sea and in the air. The reportedly (joint) "underwater patrol" comes on the heels of a recent China-Russia submarine rescue exercise hosted by Russia and a China-Russia surface warship patrol in the Northern Pacific.
China's Latest Submarine Rescue Ship Transits The Tsushima Strait Into the Sea of Japan, Draws Attention To The PLAN's Deep Sea Capabilities
On 25 July 2025, Japan’s Joint Staff Office issued a press release announcing the transit of a Chinese submarine rescue ship into the Sea of Japan by way of the Tsushima Strait. The People’s Liberation Army Navy (PLAN) submarine rescue ship in question is hull #841, which is designated the
It also explains the unusual surface transit of a Russian diesel-electric submarine and two accompanying surface ships through the Tsushima Strait.
