Ukraine’s state security service (SBU) said it carried out the first-ever uncrewed underwater vehicle (UUV) attack on a Russian vessel. The strike was on a Project 636 Varshavyanka class, or Improved Kilo class diesel-electric submarine, in the Black Sea naval stronghold of Novorossiysk. It would mark a historic first successful use of a UUV as an anti-ship attack weapon.
The SBU released a video it says shows the submarine docked at Novorossiysk along with several other ships. The video pans from right to left and at about the 16-second mark, the submarine erupts in an explosion. That means the UUV, which is not visible in the video, was able to navigate a packed harbor to strike a specific vessel. While we cannot independently verify the SBU claim about the use of a UUV in the strike, they did confirm that assertion to us directly.
Russia, meanwhile, denies any damage was caused by the attack.
‘The information disseminated by special services of Ukraine about the alleged ‘destruction’ of one of the Russian submarines in the bay of the Black Sea Fleet’s Novorossiysk naval base does not correspond to reality,” the Russian Defense Ministry (MoD) claimed on Telegram. “Not a single ship or submarine as well as the crews of the Black Sea Fleet stationed in the bay of the Novorossiysk naval base were damaged as a result of the sabotage. The watercraft serve normally.”
Today’s UUV attack appears to be the culmination of Ukraine’s development of these weapons and once again shows that the war-torn country is at the forefront of modern drone warfare innovation. Little is known about the Sub Sea Baby UUV, not to be confused with the highly adaptable Sea Baby uncrewed surface vessels (USVs) that have wreaked havoc on the Russian Navy.
Ukraine is developing several UUVs, at least that we know of. It released images in September 2023 of a UUV dubbed Marichka, designed to launch kamikaze attacks against ships and maritime infrastructure. That followed the announcement earlier that year of another UUV known as Toloka, which you can see in the following video.
Being able to operate underwater not only helps greatly in avoiding detection and destruction, but it can also potentially mitigate some defensive barriers Russia has already built around ports as a result of Ukraine’s uncrewed surface vessel (USV) campaign. This onslaught has already kept Russia’s Black Sea Fleet (BSF) at bay, forcing it to retreat from Crimea to Novorossiysk. Ukrainian USVs have also damaged enemy military facilities in occupied Crimea and the Kerch Bridge, You can see one Ukrainian USV being destroyed below.
The U.S., China and many other nations are developing their own UUVs for missions like the one that struck the Improved Kilo class submarines. UUVs can provide the ability to strike vessels and other targets at long distances and can be launched from submarines and motherships, extending their range. They can also be used for reconnaissance and mine laying, among other duties. You can read more about these vessels in our catalogue of stories here.
In the case of the Improved Kilo class boat, “the vessel suffered critical damage and was effectively put out of action,” the SBU claimed. “On board the submarine were four launchers for ‘Kalibr’ cruise missiles, which the enemy uses to strike at the territory of Ukraine.”
The submarine damaged by the Sea Baby UUVs is one of six Improved Kilo class boats that were operated by the Russian Black Sea Fleet, a retired Russian Navy officer who uses the @Capt_Navy X handle told The War Zone.
These submarines are quite capable and can be very hard to detect when dived and running on battery power. These submarines carry Kalibr long-range cruise missiles that have frequently been used to attack Ukraine.
The Sub Sea Baby UUV attack “was a joint operation of the 13th Main Directorate of Military Counterintelligence of the SBU and the Naval Forces of Ukraine,” SBU explained, adding that the estimated cost of one of the Russian submarines is about $400 million.
This incident also marks the second time an Improved Kilo class submarine in Crimea was attacked by Ukraine. In September 2023, the Rostov-on-Don was severely damaged during a combined missile and uncrewed surface vessel (USV) attack on Sevastopol. Ukraine later claimed it was destroyed. You can see the damage to that submarine below.
If today’s attack did damage the submarine significantly, Russia would be left with four examples operating as part of the Black Sea Fleet.
While much about the Sub Sea Baby UUVs remains a mystery, a proven ability to use them as weapons holds Russian vessels at even greater risk. Novorossiysk was seen as something as a relative safe haven for the Black Sea Fleet, although aerial and sea drone attacks have occurred there. But the idea that Ukraine can use underwater drones to strike ships in port there changes this calculus, if that is indeed the true method of the attack. As a result, we will also be seeing a change in Russia’s defensive posture at the sprawling port located on the northeastern edge of the Black Sea.
At the same time, if this attack was executed by a UUV, it would be another world first and is likely a harbinger of things to come. Hitting ships in port over great distances via underwater drone attack is an asymmetric capability. It’s also one that America’s adversaries are investing in heavily, and especially China.
With all this in mind, the attack on the submarine serves as another reminder that the war in Ukraine has become a conflict where theory and development are put into practice.
Contact the author: howard@thewarzone.com