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.
Given the clear porosity of our borders, I do think it is absolutely right to worry about Russian or Iranian saboteurs getting into the country with a handful of DJIs, driving up to Brize, Devonport or Faslane or Lossiemouth and knocking out our completely exposed hardware in the opening hours of a hot war. We really ought to be much more careful
They Could probably buy Drones on line…???
Are assets aren’t. We have a load of assets on NATO eastern border and in the likes of Cyprus etc that are highly exposed. Iran has already said UK bases are a valid target so if the fighting kicks off again then problems could occur. Russia isn’t a imminent threat but also solutions like this take time to sort and waiting to the threat already exists is too late.
There will be ways to reach Faslane or any other part of the UK. We have very little border security, so quite conceivable there are Russian sleeper units in the UK equipped with smuggled drones ready to launch a Spiderweb type op. Or What Ukraine has done and send drone boats near to the UK acting as a launch pad for aerial drones. I suspect Russian subs can get close too, I shouldn’t think it would be too hard to modify them to launch drones.
Its pretty certain that Russia already has equipment here for just that very effect. Why wouldn’t they? GRU aren’t mugs. We are so exposed its unreal. I mean Leftist traitors have already walked on to Brize and caused alot of damage to aircraft, its not that difficult, they only had to jump over a picket fence!
During my long and varied time in the RN I was constantly stumped by the apparent lack of security within the entrance. There is the old WW2 IRON CABLE FROM THE BEACH Welded ONTO AN IRON RINGBELOW THE ROUND TOWER. I EVEN SAILED MY LITTLE DORY FROM THE OLD H. M. S HORNET ACROSS THE HARBOUR AND ACTUALLY STOOD IN IT WHILE LEANING AGAINST THE SIDE OF THE QUEEN ELIZABETH CARRIER.. NOT A SINGLE CHALLENGE TO WHAT I WAS DOING WAS . MADE. NO SENTRY. I KNOW FROM EXPERIENCE THR FREQUENCY OR LACK THE MOD HARBOUR PATR BOATS TOOTLES AROUND THE HARB. IMAGINE IF A TERRORIST DID THE SAME THING AS I DID AND PUT A BOMB ON A CARRIER MOORED IN THE NAVAL BASE AND SUNK IT AT ITS MOORINGS THE NATION, THE NAVY WOULD BE HUMILIATED. IF NOT PUT OUT OF ACTION ESPECIALLY WHEN THERE IS NO DRY DOCK TO FIX IT IN. THE NAVY IS FUCKED FROM THE FRONT DOOR AT H. M. S RALEIGH WHEN PEOPLE JOIN TO THE EXIT FROM H. M. S NELSON ON DISCHARGE.
Spot on …our Military installations including our Dock yards and buildingyards are incredibly vulnerable to Drone attack..But a head in the sand policy seems to be the way forward for the M.O.D..!
The Excuse are probably the only forward thinking they’ve done..!!
Russia is not going to attack NATO when it cannot even defeat Ukraine without maximum effort. The only credible scenario for such a move were if Russia had in mind a fast escalation to the nuclear level … and in such a scenario it would not really matter what was protecting Faslane or what was lined up on the tarmac at RAF Marham.
Wonder if the Russians might soon consider European NATO without the Americans easier than the stubborn Ukrainians…?
Any attack will be Greyzone. Deniable. Like poisonings in Salisbury. It was a home-grown terrorist, not us. Confusion will be spread. The idea isn’t just to avoid attack. It’s to make the whole thing ambiguous enough that any response will split NATO. Especially right now the US.
That is distinctly possible and in that respect, the DIP was right in focusing some attention on vital points protection.
This story reminds me of something I read years ago about the RN submarine squadron based in Malta during the siege. A captured German aircrew was asked why they hadn’t attacked the submarines in the harbour while he was standing on the harbour side (can’t remember why his captors had taken him there). He answered that they knew they were decoys and that the real submarines were safely moored submarine pens on the other side of the island. Just then the air sirens wailed and the submarines all submerged in front of him. Apparently is face was a picture!
According to Google AI, planned pens were started before the war but they ran out of money so the project was abandoned! The 10th Submarine Flotilla was ordered to submerge during daylight raids and were painted cobalt-blue to blend into the deep Mediterranean harbour of HMS Talbot (Manoel Island), so the story may or may not be true. 🙂
Skimping on infrastructure sounds a tad familiar .!?
Cheers CR
I’d not heard that story before, thanks mate.
CR,
Excellent and amusing post. 😁 Unfortunate that RN never followed through w/ plan to create submarine pens at Gibraltar during WWII. Probable protection from everything short of a B61-13 at max yield. Perhaps a future project at HMNB Clyde w/ the 1.5% GDP dedicated to defence infrastructure? MN is still successfully utilizing the sub pens at Brest 80+ yrs. later. Difficult target set even w/ current gen conventional munitions.
Yeh, I wonder how may sub pens are buried under a mountain 🙂
Nice thought. As for the Clyde the MoD are reportedly spending £15b upper grading the facilities, everything from accommodation to maintenance and storage, the latter I think includes munitions. Project Euston, the floating docks is how apparently going to deliver 3 rather than the original 2 floating docks which has got to be one of the very few times a defence project as actually been expanded rather than cut back! Although the cynic in me thinks that the MoD traded something else in for that one..! Total spending on the RN bases is about £26b. About time too, but no harden pens though. 🙁
I Still like the idea of a sub pen under the Rock 🙂 Cool idea mate.
Cheers CR
The boom patrol would keep out sea drones, they were quite effective against torpedoes and subs in WW2 just need a bit of a re-think. And of course inflatable decoys too. Now if we can just figure out how to protect Amazon warehouses then we shall win the war!