Ukraine’s SBU domestic security service said on Monday that Kyiv’s forces struck a Russian submarine in the port of Novorossiysk, causing critical damage to the vessel.
In a statement, it added the Kilo-class submarine was knocked out of operation following the first such attack by Sea Baby drones.
СБУ вразила підводний човен рф у Новоросійську
Деталі за посиланням ➡️ https://t.co/2PjfguPVnM pic.twitter.com/pU2LIr7DP0
— СБ України (@ServiceSsu) December 15, 2025
Ukrainian news outlet UNN reported that the joint operation was carried out by the 13th Main Directorate of Military Counterintelligence of the SBU and the Ukrainian Navy.
Russian submarine taken out of action
The report added that the Varshavyanka-class submarine, which costs around $ 400 million, “was effectively put out of action.”
According to SBU, when it was hit, the Russian submarine was carrying four launchers for Kalibr cruise missiles, “which the enemy uses to strike targets in Ukraine.”
Why the strike is significant
Ukrainian officials said this operation marked the first time in history that underwater strike drones had been used successfully against a submarine of this class, demonstrating further evolution of Ukraine’s maritime campaign.
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“The damaged boat was forced to remain in the port of Novorossiysk due to successful special operations by Sea Baby surface drones, which drove Russian ships and submarines out of Sevastopol Bay in the temporarily occupied Crimea,” the SBU said.
Ukrainian navy spokesperson Dmytro Pletenchuk said the operation to hit a submarine – the most difficult target to hit – marked “another turning point” in the naval battle between Ukraine and Russia.
“This day once again upends the perception of the possibilities of naval combat in this war,” he told Reuters.
It will be hard for Russia to repair the submarine as that would have to be done above water, which would mean the vessel would again be exposed to attack, he added.
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Russia has now lost one of its four submarines stationed in Novorossiysk, three of which are Kalibr-carriers, Pletenchuk added.
Ukraine steps up attacks on Russian naval assets
In recent weeks, even as the peace talks continue, Ukraine has been stepping up its drone attacks on Russian ships and naval infrastructure, significantly impacting Russia’s Black Sea Fleet.
Ukraine has repeatedly targeted Russia’s “shadow fleet” of oil tankers used to bypass international sanctions.
Details on Ukraine’s takedown of another Russian shadow fleet tanker are only getting more interesting.
Tanker DASHAN had NO registration. The Gambian flag it showed two days ago while passing through the Bosphorous was a fake and before that the tanker had a fake Comoros flag… pic.twitter.com/wgvVDGo3FI
— Jay in Kyiv (@JayinKyiv) December 11, 2025
In November, Ukrainian naval drones struck two sanctioned oil tankers, the Kairos and the Virat, off the Turkish coast.
