Ukraine Claims Historic Underwater Drone Strike on Russian Submarine

 Ukraine’s Security Service (SBU) has claimed responsibility for a groundbreaking underwater drone attack that reportedly struck and disabled a Russian Kilo-class submarine at the naval base in Novorossiysk on the Black Sea. Ukrainian officials describe the operation as a first in military history, where unmanned underwater vehicles were used to successfully target a submarine docked in port. 

Details of the Operation

According to the SBU, the mission was carried out on December 15, 2025, using specially developed “Sub Sea Baby” underwater drones. These autonomous underwater vehicles reportedly penetrated the defenses of the heavily guarded Russian naval base and detonated near the stern of the Varshavyanka-class (Project 636.3) submarine, causing critical damage that put the vessel out of service. 

The submarine targeted is believed to have been equipped with four Kalibr cruise missile launchers, weapons that Russian forces have repeatedly used in strikes against Ukrainian cities and infrastructure. Ukrainian authorities highlighted the symbolic and strategic nature of the target. 

Ukrainian officials have hailed the strike as a military milestone, marking the first known use of underwater drones to neutralize a submarine. Analysts say this reflects a significant evolution in unmanned maritime warfare and underscores Kyiv’s tactical innovation amid the ongoing conflict. 

Experts point out that the operation’s success required complex navigation and stealth capabilities, enabling the underwater drones to bypass conventional harbor defenses. This development may prompt reassessments of naval base security and anti-drone countermeasures worldwide. 

Russian Response

The Russian Black Sea Fleet has rejected Ukraine’s claims, asserting that no submarine or other vessels at the Novorossiysk base were damaged and that operations remain normal. Moscow did not provide independent evidence to counter Ukraine’s footage and statements. 

The reported strike comes as Ukraine continues to rely on asymmetric warfare technologies — including surface and underwater drones — to challenge Russia’s naval superiority after losing much of its own fleet earlier in the conflict. These innovations have previously forced parts of the Russian Black Sea Fleet to relocate from Sevastopol in Crimea to Novorossiysk. 

This latest episode underscores how unmanned systems are reshaping modern combat, enabling smaller forces to inflict disproportionate effects against larger, conventionally superior adversaries.