On 12 May 2026, commercial imagery from a Vantor satellite captured two Borei-class ballistic-missile submarines moored beneath anti-drone netting at Rybachiy, the Pacific Fleet's strategic submarine base on Kamchatka. Rybachiy lies roughly 7,400 kilometres (4,600 miles) away from the Black Sea. H I Sutton, who first identified the structures, recorded a force-protection barrier built against a threat that has never operated within thousands of kilometres of the Russian Pacific coast. By 4 August 2026, fresh Vantor images showed multiple submarine classes at the base under nets, with crane barges working along the berths.
No public disclosure from Kyiv regarding Ukraine's own maritime-drone programme records its impact quite as clearly as that single photograph. Russian harbour defence can be tracked, dated and tallied in ways Ukrainian capability is not and should not be. Analysts can count barrier lines off commercial imagery. They can count barges. The calendar dates when each tier appeared can be pinned down. Read in full from October 2022 to September 2026, that record reveals a naval force that has piled on defensive layers for four straight years without ever being able to take one down.
What Russia Has Actually Built
The layout is not a single barrier. It is a stack.
At Sevastopol, Sutton logged roughly six defensive layers by 23 April 2023, featuring two extra floating-net lines and a string of six large pontoon barges constricting the harbour entrance. By June his count stood at no fewer than five layers, working alongside fast patrol boats, helicopters and at least two DP-64 anti-saboteur systems. Shifting between five and six is no contradiction: crews reposition floating barriers, and satellites took the two image sets weeks apart. Each total depends on a named analyst interpreting photos without full technical provenance, which is why neither grades above single-source evidence. In May 2023 The War Zone identified what looked like a BM-21PD/DP-62 Damba anti-diver rocket launcher mounted on the entrance breakwater, revealing how Russian naval commanders catalogued the threat: as port sabotage, tackled with port-sabotage gear.
Novorossiysk received defences later and on different terms. Commercial imagery from 30 March 2024 revealed four barges moored to choke the approach to the naval base, a layout British defence intelligence independently flagged. The public record never established whether those four vessels were profitable commercial freighters pulled from civilian trade or cheap expendable hulks, so any financial estimate of lost trade rests entirely on speculation.
Russian official statements evolved alongside the physical build-out. The governor of Sevastopol acknowledged a surface-drone strike on 29 October 2022, emphasising that his defences had repelled it. By May and July 2023 the Russian Ministry of Defence described "unmanned speedboats" as a common attack type, claiming crews on the Ivan Khurs had destroyed three and the Sergey Kotov two using standard deck weapons. On 13 October 2023 the Black Sea Fleet formally drilled patrol ships, minesweepers and anti-saboteur craft to hunt down and kill naval drones. On 17 March 2024 Defence Minister Sergei Shoigu ordered crews to mount extra heavy machine guns across the fleet and run round-the-clock training against unmanned motor boats. Two months later the Russian firm Laboratory PPSh said it was adapting thermal sights for PKM and Kord machine guns in direct collaboration with Black Sea Fleet gunners, claiming target detection beyond one kilometre.
That is what routinisation looks like. A freak security crisis in 2022 had turned by 2024 into a permanent fleet training, procurement and industrial burden.
The open record cannot provide the exact geometry that naval engineers actually require. For neither harbour does verified data establish total boom length, netting depth, anchor spacing, gate width or gate opening times. Overhead commercial imagery works well enough to tally barges and spot surface booms. It cannot tell analysts what hangs beneath the waterline.
The Storm That Priced the System
The most compelling evidence of what this system costs to maintain came from the weather, not an attack.
On 27 and 28 November 2023 a ferocious storm struck Sevastopol with recorded winds exceeding 90 mph (145 km/h). Planet Labs imagery taken on 28 November, assessed by Howard Altman at The War Zone against an 11 November baseline, showed severed boom lines and several barges dragged away from their positions. The failure mechanism was simple. A heavy floating barrier consists of moorings, shackles and buoyant pontoons, and violent wind and wave action tears through those connections rather than shattering the individual pieces.
Repair work was visibly moving within days, as satellite photographs showed primary barriers towed back into place around 2 December. But on 7 December Ukrainian Navy spokesman Dmytro Pletenchuk calculated that crews had restored only about 60% of Sevastopol's boom network.
Those two assessments do not contradict each other, and the space between them holds the core finding. Towing floating barriers back roughly into place is quick work. Checking seabed moorings, re-tightening underwater netting, re-certifying gate mechanics and restoring full operational readiness takes far longer. Surface alignment and combat readiness are completely different measures, and orbiters only photograph the water's surface.
Russian authorities release no figures on what any of this costs. To understand lifecycle expense rather than initial construction, a 2025 US NAVSEA procurement vehicle for maritime security barriers sets a $199 million ceiling across several vendors, bases and years, paying for installation, refits, engineering, inspections, mooring repairs and waterfront support. That budget cap cannot simply be divided by metres of boom and pasted onto Sevastopol. The contract proves that a barrier network creates an unending maintenance burden rather than a one-time capital purchase, and Russia has shouldered that bill across two harbours at the same time since 2023.
December 2025 and the Second Line
On 15 December 2025 an underwater detonation went off beside a Project 636.3 submarine docked at Novorossiysk. Personnel from Ukraine's SBU said the strike hit and disabled the boat. Russian officials insisted neither the submarine nor its crew took any damage. Neither side has retracted its account through 15 September 2026.
The physical evidence lies between both claims, and it points in one direction. Vantor imagery from 16 December revealed heavy cratering along the quay next to the targeted vessel, but satellite passes cannot confirm internal hull damage. British defence intelligence later assessed the submarine as highly likely to be B-271 Kolpino and significantly damaged. The most revealing single clue appeared four weeks later: Planet imagery from 19 January 2026, scrutinised by Radio Liberty editor Mark Krutov, caught the suspected Kolpino occupying the exact spot it had held for 35 days while adjacent submarines shifted berths. A Kalibr-capable boat that sits motionless for five weeks during wartime is not in active service. That reality badly undermines the Russian denial without formally refuting it, while claims of "sunk" or "destroyed" remain unsupported by open evidence.
What Russian forces did next stirs far less argument than the fate of the submarine. Sentinel imagery spotted around 21 December 2025, six days after the blast, showed an extra barrier line strung inside the Novorossiysk naval basin to reinforce, rather than replace, the outer defences. Provenance for this imagery remains thin, lacking named high-resolution analyst confirmation, meaning the dates are more certain than the precise layout.
The strategic weight rests on the reality of that second line rather than its exact length. Erecting an inner barrier proves Russian naval planners no longer trusted a lone harbour-mouth boom to shield high-value submarine berths from the rest of the anchorage. That is defence in depth. It does not prove the outer barrier had failed, because the December attack introduced a different class of weapon and public sources do not show how it got in.
Cages, Nets and the Admission They Carry
A Vantor image from 13 June 2026 delivered the most revealing single frame of the campaign, and the most widely garbled.
Simplified reporting claimed three submarines had submerged at Novorossiysk. The assessment from British intelligence proved far more specific and instructive: three of four Kilo-class boats wore counter-UAS cages over their conning towers, all three were partially submerged with slackened mooring lines, and crews had moved the fourth, uncaged boat clear and submerged it as well. Four hulls down, three of them caged. Four days later, Vantor imagery obtained by The War Zone showed those same submarines surfaced at their standard berths.
That four-day reversal answers a riddle a single still image cannot resolve. Ballasting down while tied to the pier is an active, repeatable force-protection drill rather than a permanent docking stance. Observers logged similar behaviour in 2024, so the tactic is not new either. The toll it takes remains largely hidden: restricted deck access for repair crews, awkward alongside maintenance, extra watchkeeping and ballast management. Arguing that this drained batteries or accelerated hull fatigue outruns the available evidence, especially since the June imagery showed conning towers sitting above the waterline.
The cages themselves are often mislabelled. Shaped against overhead attack geometry, they shield delicate sensor masts, optics and open hatchways. They are not underwater-drone barriers and no analyst should present them as an answer to the underwater strike of December 2025.
The stacking logic tells the true story. Fitting a cage to a submarine moored behind two harbour boom lines shows precisely how little trust planners place in those barriers. Russian commanders have fortified the same vessel three times over, and that duplication speaks for itself without needing an official admission from Moscow. The build-up of Russia's electronic-warfare network in Ukraine exhibits that exact compounding design, stacking fresh layers without stripping out old ones, driven by a simple fact: no single tier stops attacks on its own.
Seven Thousand Kilometres From the Black Sea
Geographic spread provides the clearest institutional signal in the open record, with Rybachiy standing as the premier example.
Rigging anti-drone netting over Borei-class SSBNs at a Pacific strategic base answers no direct operational danger in the Sea of Okhotsk. It marks a base-defence doctrine widened from an immediate wartime theatre to the home ports of Russia's naval nuclear deterrent. Naval spotters had already noted an early overhead canopy on the Northern Fleet's Delta-IV Tula in 2024. None of this proves the screens work. It proves that Russian admirals no longer view harbour vulnerability as an isolated Black Sea headache.
The institutional paper trail points in that identical direction. Russia established what news reports in July 2026 described as its first dedicated naval uncrewed-systems regiment in the Northern Fleet, with follow-on units planned across its other fleets. That unit is not an anti-drone detachment and should not be labelled as one, but standing military organisations reveal institutional thinking far better than official proclamations. An essay in the General Staff journal Voennaya Mysl in 2026 categorises naval robotic systems as an enduring pillar of maritime doctrine rather than an ad hoc wartime stopgap.
No dedicated Black Sea Fleet headquarters focused entirely on counter-drone tactics has surfaced. Russian anti-saboteur units existed long before this conflict: military dispatches from February 2022 described Grachonok-class craft, Raptor boats, underwater sensors and more than 200 personnel drilling in naval-base defence. The post-2022 transformation reflects widened missions, reinforcement and hardware retrofits rather than inventing base security from scratch. When a Grachonok-class craft was itself photographed beneath overhead netting in May 2026, it captured the entire predicament: the guard boats now need guarding.
Allied navies are digesting that very lesson. NATO's 2025 maritime exercises incorporated counter-uncrewed-vessel drills, planners formed Task Force X to direct autonomous vehicles for persistent offshore reconnaissance, and a 2026 report by Navy Lookout on ships in port assessed berthed warships at protected anchorages as newly exposed. The vulnerability driving Russian defence budgets is treated worldwide as a shared reality.
What the Ledger Can and Cannot Show
No reliable financial total exists for this enterprise, and inventing one would be an error.
Russia publishes no dedicated budget entry for anti-drone port protection, no per-metre price for its boom lines, no flight log for Black Sea helicopter sorties and no payroll tracking reassigned troops. What analysts can document is a physical footprint: four barges along a single Novorossiysk line, five to six barrier tiers with around six pontoon barges during peak deployments at Sevastopol, recurring storm-damage repair, three of four Novorossiysk submarines fitted with cages, and roughly nine acres cleared with an approximately 100 by 40 metre foundation laid at Ochamchire in Abkhazia by July 2024, tracked by Bellingcat's Logan Williams using Planet SkySat imagery.
Aviation shows why analytical discipline matters. Sutton reported by December 2023 that Russia had stood up specialist units using Mi-8 and Ka-27-family helicopters to fight maritime drones, with Be-12 flying boats handling search and tracking, while Russian state outlets broadcast video of Ka-29 and Mi-8 crews firing on small waterborne targets in November 2023. Tasking is documented. Tempo is not. Keeping a single helicopter continuously on station consumes 8,760 airborne hours a year before factoring in transit and handover flights, but no verified data shows Russia flies continuous patrols, and multiplying those hours by Western operating costs invents false precision. The real cost is mission displacement: a Ka-27 patrolling harbour approaches is not hunting submarines or running search-and-rescue sorties.
That same caution applies to the overarching conclusion. Maritime drones alone did not force the Black Sea Fleet to curb operations in the western Black Sea. Cruise missiles, aerial drones, sea mines, lost warships, maintenance constraints and shifting Russian military goals all belong in the same causal equation, which mirrors the cost-exchange attrition seen in Russia's air-defence expenditure in a maritime environment. The solid analytical claim is that Ukraine has driven sustained Russian defensive spending. Any assertion attributing a precise percentage of reduced Russian fleet activity to uncrewed surface craft collapses under scrutiny.
Fleet dispersal has not reversed. No lasting return of primary warships west to Crimea has appeared since 2024, and Naval News identified Novorossiysk as the Black Sea Fleet's main operating base by March 2026. The 12 August 2026 strike on Novorossiysk and the follow-up strike on 9 September 2026, after which battle-damage imagery revealed hits on the Admiral Essen, the Admiral Makarov and a Buyan-M-class ship, both confirm that major combat vessels remained gathered there.
Ochamchire qualifies the trend. It remains an expanding auxiliary anchorage rather than a proven substitute base, and nothing in open reporting proves it possesses Sevastopol-grade dockyards, weapons-loading cranes or maintenance berths. Bellingcat investigators explicitly cautioned that the function of individual new facilities remained unverified.
Strategic Implications for Ukraine
The physical record of Russian base hardening yields four operational takeaways for Ukrainian and partner staffs assigning maritime resources through 2027, each rooted in verified Russian behaviour rather than asserted combat results.
- The escalation curve forms the core argument, not the financial balance. Sevastopol barriers, storm repairs, the Novorossiysk barge cordon, eastward basing, a second barrier after December 2025, submarine cages, ballasting down at the pier, Pacific berth netting. That chain of events is documented, dated and far harder to contest than contested claims about percentage denial rates. Briefings to Ukrainian and European leaders that lead with a rouble figure invite a methodology fight they cannot win. Briefings that walk through that chronological sequence avoid the argument entirely.
- Stacking defences without removing older tiers signals an unsolved vulnerability. Russian forces have piled on layers for four straight years without taking down one. Had commanders judged any single barrier sufficient, the cheaper cordons behind it would have vanished. They remain intact, and fitting a cage to a submarine berthed behind two barrier lines inside a dispersed base proves it. The absence of any drawdown exposes Russian institutional concern far better than any ministry announcement.
- Defensive presence must never be conflated with interception. The 22 March 2023 attack on Sevastopol achieved a documented partial breach, with uncrewed craft slipping past the outer boom before defenders destroyed them inside the harbour. The 24 April 2023 attack was described as beaten back with zero signs of penetration. The counter-UAS conning-tower cages and Pacific pier netting lack any confirmed test in combat. Reporting that mistakes a photographed net for an impermeable shield grants Russian forces an operational success they never proved, while treating every Russian countermeasure as useless makes the exact opposite mistake.
- Dismantled defences will provide the true indicator. A lasting return of capital warships to western Crimean roadsteads, a thinning of harbour barrier lines, or a steady revival of standard fleet sorties would prove restored Russian naval confidence far better than official press statements. Not one of those three markers has emerged through 15 September 2026. Ukrainian planners have a low-cost, open, reliable metric to monitor, and it currently points in their favour.
The most credible interpretation of four years of Russian harbour engineering is not that the cordons have failed. Several held, several were breached, and most have never faced public combat trials. Rather, Russia must now keep up a layered, dispersed and permanent institutional defensive posture just to keep them functional, across two operational ports, protecting submarine berths across three separate fleets, and against weather that regularly rips the entire floating apparatus apart.
The critical development to watch is not another barrier installed. It is one taken down.
