Three of the Russian Black Sea Fleet’s four Kilo class submarines have been fitted with counter-drone cages over their conning towers, and satellite imagery has shown the vessels partially submerged inside their own harbour at Novorossiysk, according to British Defence Intelligence.
In an intelligence update published on 4 August, the Ministry of Defence said the cages had been applied “as a preventive measure in response to Ukraine’s increased ability to strike targets further from the front line.”
Latest Defence Intelligence update on the situation in Ukraine – 04 August 2026.
Find out more about Defence Intelligence’s use of language: https://t.co/LD3hsOHHYW#StandWithUkraine pic.twitter.com/RFWDQYmXv9
— Ministry of Defence 🇬🇧 (@DefenceHQ) August 4, 2026
The behaviour was recorded in commercial satellite imagery dated 13 June 2026. Defence Intelligence said analysis of the imagery “identified that three of the submarines had loosened their moorings and had submerged within the basin.” It added: “Whilst the majority of the hull was below the surface, their conning towers remained above the waterline, explaining the need for the counter-UAS cage.”
A fourth boat behaved differently. According to the update, it “had not been fitted with a counter-UAS cage, had slipped its mooring lines, manoeuvred away from nearby surface vessels and submerged within the harbour, its conning tower visible above the waterline.” Defence Intelligence assessed that “the lack of a counter-UAS cage likely signifies this vessel has been de-prioritised compared to the other three.”
Submerging alongside is not a normal peacetime practice for conventional submarines in harbour, and the imagery points to crews accepting the wear and operational inconvenience of sitting on the bottom of a basin rather than remaining fully surfaced at their berths.
Novorossiysk, on Russia’s Krasnodar coast, has become the principal base for much of the Black Sea Fleet after sustained Ukrainian attacks on Sevastopol in occupied Crimea forced Moscow to disperse its warships eastwards. The port has itself been struck repeatedly, and the submarine Rostov-on-Don was damaged at Sevastopol in a 2023 missile strike and later reported sunk following a further attack in 2024.
The Kilo class boats, known to NATO as Improved Kilo and designated Project 636.3 by Russia, are diesel-electric attack submarines armed with Kalibr land attack cruise missiles. They have been used through the full-scale war to launch strikes against targets across Ukraine, and their ability to fire from submerged or protected positions has made them among the more difficult Black Sea Fleet assets for Ukraine to neutralise.
Improvised cages and screens have proliferated across Russian equipment during the war, most visibly the so-called cope cages fitted above tank turrets, and more recently netting strung along supply routes to catch first-person view drones. Their appearance on submarine conning towers reflects the extension of that threat to naval bases far behind the front line.
The update was issued as part of the regular series of Defence Intelligence assessments on the war in Ukraine published by the Ministry of Defence. The imagery accompanying it was credited to Vantor and provided by European Space Imaging.
I think the west tends to look down on Russian make shift attempts to protect it’s assets, rather than doing the more sensible thing of learning from them. We saw the consequences of this when Iran hit the US jets all stacked at the same airport, lessons not learnt.
There is a difference between lazily leaving an AWACS parked at the same spot on a runway for a few days and having to keep your submarines submerged at one of your main naval bases.
Imagine these Donkeys going to war with NATO and Murmansk being with in easy short range drone distance of Finland. A handful of soldiers with Hornets might knock out the entire Northern fleet in a few minutes.
It’s warfare like this that the UK is preparing for. In today’s world a moderate sized unit like 45 commando with drones and missiles can cause major strategic effects. Especially for an area as isolated as the Kola Peninsula.
And a Russian sabotage unit similarly equipped with Drones could not, if it managed to reach the area of Falsane / Coulport / Loch Long?
I agree overall, but I also agree with Steve’s point above. We continue to line up our assets like Skittles, confident nothing will reach them.
The US had its pants down on 9/11 as well, who could have known?
I’d thoroughly approve of similar defensive cages for our own assets, if such a thing were feasible. Submerging is a tad amusing, but if it works, well?
Yes mate but as you will be aware it’s a little bit further from Russia to faslane than it is from Finland to Murmansk.
Appreciated. But not impossible, that was my point.
In the reverse, as you’ve pointed out before, Finland joining NATO is a goldmine for us, so close to the border there.