Historic Marichka? UUV attack on Novorossiysk Kilo sub

Hi all,

Pete is doing fine, but Australia is mourning over the mass shooting, at Bondi Beach, on the weekend, with many security issues.

There was one incident, however, that I have to report on - the Ukrainian claim to have used a Sea Baby underwater drone to attack a Russian Kilo submarine in the Black Sea port of Novorossiysk on 15 December. 

image: Kyiv Independent
---

If true, this is an historic occasion - the first military use of an underwater drone against a hard target in a conflict. 

I believe that H.I. Sutton’s hot take video is the best analysis currently available:

Now, there are a few points I have to make:

1. The Security Bureau of Ukraine (SBU) released this video, which means that it has access to the security cameras monitoring at Russia's 'secure' naval base in  Novorossiysk, like it had access to the security camera network monitoring the Kerch Bridge in the June 2025 attack that damaged its foundations. 

2. There is not yet any confirmation on which specific Kilo submarine was attacked, but the submarine Rostov-on-Don was destroyed in Sevastopol in 2024, which leaves the Black Sea Fleet with two operational Kilo submarines, which are used to launch Kalibr cruise missiles at Ukrainian apartment buildings and infrastructure. 

There's also an unsubstantiated theory that a puff of white smoke, ten seconds after the primary charge, indicates a limpet mine detonation on a second Kilo in this video. 

The Marichka (Ukrainian for Mary) UUV. Photo courtesy Ukraine's weapons' research and development agency AMMO via Joseph Trevithick at TWZ September 25, 2023. 
---

3. The term ‘underwater Sea Baby’ is vague. It may point to the Ukrainian Marichka UUV, first identified in 2023 (see photo above and Youtube video below). Ukraine did ‘show’ the Marichka drone in 2023, but this could be a cover story. The size of this detonation, under the submarine, indicates a substantial explosive charge, very similar to the one that damaged the Kerch Bridge in July, which Ukraine claimed was a mine planted by agents. Was this attack by a UUV or naval divers? The SBU aren't saying.

Animation of Ukrainian Marichka UUVs courtesy Ukraine's weapons' research and development agency AMMO here and the Youtube here (voiceover in Ukrainian, but a picture tells a thousand words).
---

The Black Sea Kilos are an enigma, as they are only used to fire cruise missiles at Ukraine, and have spent the majority of this 'three-day conflict' staying in their supposedly secure docks, first at Sevastopol, then fleeing to Novorossiysk in October 2023.

As claimed 'modern' combatants, their employment has been meek and cowardly. A more aggressive strategy would have them out on patrol picket to spot Ukrainian USV swarms deep in the Black Sea, or to send special forces against the Odessa coastline, or conduct an anti-shipping campaign. 

Addendum 17 December 2025

The WarZone has published an article based on recent satellite images of Novorossiysk, which show that Russia has moved three of the Kilo submarines, while the targetted Kilo remains at its pier-side. The images also show significant damage to the pier, about 20 metres away from the submarine, so it could have sustained damage to its propulsion system from the pressure wave of the blast.