A French Navy frigate has been conducting surveillance of a Russian submarine operating on the surface off the coast of Brittany, according to NATO Maritime Command.
In a statement shared on social media, the command said: “We. Are. Watching. A French Navy frigate conducts surveillance of the Alliance’s maritime approaches, marking the presence of a Russian submarine operating on the surface off the coast of Brittany. NATO stands ready to defend our Alliance with constant vigilance and maritime awareness across the Atlantic.”
The activity forms part of NATO’s ongoing maritime posture across the North Atlantic, with allied ships maintaining continuous watch over surface and subsurface movements near European waters.
The submarine is understood to be the Novorossiysk (B-261), a Project 636.3 Improved Kilo II-class diesel-electric attack submarine assigned to the Russian Black Sea Fleet. The Novorossiysk was laid down at the Admiralty Shipyards in Saint Petersburg in August 2010, launched in November 2013, and commissioned in August 2014.
With a displacement of 3,100 tonnes submerged and a length of 74 metres, the submarine can remain at sea for 45 days and dive to depths of up to 300 metres. It carries six 553 mm torpedo tubes capable of firing torpedoes, mines, or Kalibr cruise missiles.
The Novorossiysk has previously been deployed to the Mediterranean in support of Russian operations in Syria. It visited the Spanish port of Ceuta in 2015, drawing criticism from British officials due to its proximity to Gibraltar, and has repeatedly rotated through the region as part of the Russian Navy’s Mediterranean Task Force.
In late September 2025, Russian social media sources reported that the submarine had suffered a serious technical issue involving a diesel fuel leak, though the extent of the damage remains unconfirmed.
Kilo recharging it’s batteries. It’s all about undersea cables.