In a historic naval operation, Ukraine successfully deployed its indigenous “Sub Sea Baby” underwater drones to strike and disable a Russian Kilo-class attack submarine docked at Novorossiysk port in Russia’s Krasnodar Region on 15 December 2025.
The strike marks the first recorded instance of an underwater drone neutralising a submarine in combat, according to Alexander Kamyshin, advisor to Ukrainian President Volodymyr Zelenskyy. Video footage released by the Security Service of Ukraine (SBU) showed a dramatic explosion near the pier where the submarine was stationed. Independent verification by Reuters confirmed the location and authenticity of the footage.
Strategic Implications
Novorossiysk has become Russia’s primary Black Sea naval base after relocating much of its fleet from Sevastopol in occupied Crimea. The damaged Kilo-class submarine, capable of carrying Kalibr cruise missiles, played a key role in Russia’s long-range strikes on Ukraine. With one submarine disabled, Russia now has only three operational Kalibr-armed submarines at Novorossiysk, reducing its regional missile projection capacity.
Ukraine’s Asymmetric Naval Strategy
Facing a conventional naval disadvantage, Ukraine has turned to asymmetric warfare using unmanned maritime systems, including sea drones and missiles, to challenge Russian dominance in the Black Sea. Ukrainian Navy spokesperson Dmytro Pletenchuk described the operation as a “turning point” in the naval theatre, highlighting the challenge of targeting stealthy submarines.
Operational and Technical Details
The “Sub Sea Baby” drones feature autonomous navigation, extended range, and warheads optimised to penetrate submarine hulls, enabling deep strikes in Russian-controlled waters. Repairing the damaged submarine would expose it to further attacks, creating a significant logistical challenge for Moscow.
Global and Doctrinal Impact
The successful strike demonstrates the growing role of unmanned systems in naval warfare and may influence global military doctrines, particularly for submarine-reliant navies. The operation also strengthens Ukraine’s bargaining position amid ongoing US-brokered peace talks.
Next Steps and Russian Response
While Russia has not officially commented on the incident, analysts expect enhanced port defences, anti-drone measures, and intensified naval patrols in response. Meanwhile, Ukraine is expected to continue investing in underwater drone technology to sustain pressure on Russian forces in the Black Sea.
