By Olha Chepil | 2026-01-22

Russia moved much of its Black Sea Fleet to Novorossiysk to escape Ukrainian attacks. The underwater strike on a submarine there showed the relocation solved the wrong problem. Geography did not fail Moscow, doctrine did. What Ukraine exposed was a fleet designed to defend against ships and missiles, not autonomous weapons moving unseen beneath the surface.

In December, the Ukrainian attack marked the first time an underwater drone, Sub Sea Baby, targeted an operational submarine inside a protected naval base. Analysts say the strike marks a shift in maritime warfare, where unmanned systems increasingly set the rules.

According to the Security Service of Ukraine, the Project 636.3 Varshavyanka-class submarine, armed with Kalibr cruise missiles, suffered critical damage and was disabled. Russian authorities confirmed an explosion but claimed it struck the pier rather than the submarine itself.

"The fact that a drone penetrated not only the waters of Tsemes Bay, but also the very heart of this geoport, is astonishing. Obviously, the Russians didn't expect this," Pavlo Lakiychuk, director of security projects at the Strategy XXI Center for Global Studies, told Kontur.

Out of action

Satellite images taken December 16 show visible damage to a pier at the Novorossiysk naval base where Ukraine says the submarine was moored at the time of the strike. While there is no direct visual confirmation of hull damage, military analysts say the destruction pattern indicates a powerful underwater explosion near the vessel.

Experts say hydraulic shock -- the force transmitted through water from the blast -- likely caused the most serious damage, even without a direct hit.

"As I understand it, the main impact hit the pier, and a hydraulic shock occurred under the boat, resulting in damage to the submarine. It is very serious," Andriy Ryzhenko, a first-rank captain in the Ukrainian Navy reserves and a strategist with Sonata, told Kontur.

Ryzhenko said the submarine's continued presence at the pier the following day, while other vessels were removed, strongly suggests it could not be moved.

"The main evidence is that the submarine remained in its old position the next day, while other ships and boats were removed. This suggests that it simply cannot be transported," he said.

He noted that combat-ready ships typically leave an area immediately after an attack or disperse to avoid further strikes. The failure to do so points to severe damage.

Ryzhenko said observers are watching for signs the submarine is eventually towed away, which would indicate partial restoration. Current assessments, he said, suggest the vessel may have partially sunk, sustained damage to its stern compartment and lost mobility.

Even if the hull remains intact, the submarine has lost its combat value.

"Of course, it can't fire Kalibr missiles. The submarine launches these missiles from underwater, from depths of about 50 meters. It is not able to do this while at the pier. So, when it comes to combat, this submarine is definitely out of action," Ryzhenko said.

Repairs would likely take at least a year and possibly longer, Ryzhenko added. He questioned whether facilities in Novorossiysk or Sevastopol are capable of carrying out such extensive work.

Underwater revolution

Beyond the immediate damage, analysts say the strike set a technological precedent. For the first time, an underwater drone attacked a submarine inside a heavily defended port, challenging long-standing assumptions about naval security.

Ukrainian officials say Russia had been using the diesel-electric submarine, equipped with four Kalibr launchers, to strike Ukrainian cities. The vessel was stationed in one of the most secure zones of the Novorossiysk base, protected by multiple layers of defenses.

"This was quite a challenging action," Ukrainian Navy spokesman Dmytro Pletenchuk told Kontur.

He said concerns over Ukrainian strikes had already pushed Russia to limit the presence of its ships and submarines in the Black Sea, showing how seriously Moscow viewed the threat.

Despite those precautions, Ukrainian drones breached the defenses, demonstrating both technical sophistication and extensive planning.

"The operation had many layers, from developing the weapon to leak-free planning. Carrying out such an action was very difficult," Pletenchuk said.

Lakiychuk said the key factor was the drone's ability to penetrate waters long considered inaccessible.

"To hit a target there, you have to pass through the gate, enter the inner perimeter and deliver the strike. To reach the submarines, you have to go even deeper. The site was considered very well protected," he said.

Breaching such defenses required a weapon designed to operate where ships and aircraft cannot.

According to Defense Media, the Sub Sea Baby underwater drone is designed for stealth and long-range missions. It operates autonomously without antennas or direct communication with an operator.

Earlier, Ukraine unveiled three variants of the Toloka underwater drone, which resembles a large torpedo and incorporates artificial intelligence to conduct missions without human intervention.

Navy without fleet

Ukraine does not have a full-fledged navy, yet analysts say it has destroyed or disabled about one-third of Russia's Black Sea Fleet since the start of the full-scale invasion.

"Using naval drones, Ukraine is disrupting the concept of traditional naval warfare," Lakiychuk said.

After repeated strikes on Sevastopol, Russia transferred much of its fleet to Novorossiysk. The latest attack shows that defensive measures there were also insufficient, while repair options remain limited.

Two other Project 636.3 submarines were transferred to Syria before the war and are now undergoing repairs in Saint Petersburg. Under the Montreux Convention, Turkey bars military ships and submarines from transiting the Bosphorus during wartime, preventing their return to the Black Sea.

Ryzhenko said an inland route via the Volga-Don Canal exists in theory but is unlikely due to the submarine's size.

The Novorossiysk strike fits a broader pattern. Ukrainian naval drones have targeted the Crimean Bridge, military sites in Crimea and even destroyed a Russian Su-30 fighter jet over the sea. In September 2023, Ukraine struck the submarine Rostov-na-Donu during repairs in Sevastopol.

"Ukraine is demonstrating that a navy is no longer needed to strike maritime targets. Technology allows attacks that previously required a group of ships or aircraft," Lakiychuk said.