By Chief Warrant Officer (CWO) Angel Peiro

On October 29, a combined attack from Ukraine (UKR), Unmanned Air Vehicles (UAVs) and Unmanned Surface Vessels (USVs) struck the Russian (RUS) Sevastopol Naval Base, allegedly damaging an Admiral Grigorovich-class frigate and a Natya-class minesweeper. This event provides an opportunity to analyze the evolution of USV improvised explosive devices (IEDs) and their potential impact on future maritime warfare.

The waterway breached by the USVs before striking the Russian warships. (Source Via

Plan of a French Brulot fireship, 1792.

With all the thrill of a daring commando raid recorded in Hollywood, footage of the attack went viral on the internet. A combined air and maritime attack with drones, potentially the first time ever, struck the Russian naval base of Sevastopol, Crimea. Also, this is the first use of explosive laden USVs in a conventional war with asymmetric warfare tactics. 9 UAVs and 7 explosive laden USVs managed to surprise the Russian Black Sea Fleet, being able to hit at least 2 Russian surface units: the Admiral Makarov frigate, acting as the flag ship after the sinking of missile cruiser Moskva on April 14, and the Ivan Golubets minesweeper, possibly damaged and neutralised. Regarding BDA, apparently the frigate is patrolling again with minor damage, and the minesweeper is still moored.

On November 18, reportedly a Ukraninan USV struck the Sheskharis oil terminal in Novorossiysk at night, on Russia ́s Black Sea coast, with a significant impact on tanker traffic destined for export. This strategic oil infrastructure is very close to the main Russian naval station on the Black Sea before the Crimean illegal annexation in 2014.

A Little bit of History: from fireships to USVs.

The asymmetric naval warfare tactic of fireships is rooted as far back as 208 AD in the Battle of Red Cliffs on the Yangtze River, in ancient China. With the invention of the Greek fireship in the 7th century, there exists a lot of recorded usage of fireships during the age of the fighting sail, from the Crusades; the Anglo-Spanish War; the Thirty Years War; or the Greek War of Independence.

During WWI, the Imperial German Navy used the FL-boat (Fernlenkboot, literally “remote controlled boat”) against the British Navy. It was a command- wire, remote-controlled motorboat, 17m long, carrying about 700 kilograms of explosives, with the wire 20 kilometres long. There are 2 recorded impacts in 1917.

More recently, in 2000 a deadly attack from Al-Qaeda on the USS Cole in the port of Aden by a SWBIED (Suicide Water Borne IED) introduced again the old TTP as a new form of asymmetric naval warfare.

Houthi rebels, backed by Iran, severely damaged the Saudi frigate Medina using a remote-controlled WVIED in the Red Sea in January 2017. Later, the Houthis launched other WBIED (Water Borne IED) attacks on civilian tankers in the Red Sea and the Saudi auxiliary shipping carrier Buraidah at King Faisal Naval Base in Jeddah during December 2020.

To go deeper on this subject, the article “The perfect storm: unmanned IED threat in the maritime environment”, by Lieutenant Colonel Jose M Rufas was published in this magazine in 2020 Spring/ Summer edition.

WWI cable-controlled explosive Fernlenkboot being rolled into its shelter at Zeebrugge, Belgium, circa 1916. (Source:

Photo released by the Saudi-led coalition in Yemen on 4 March 2020 showing the new fishing boat design for the Houthi suicide drone boat program. (Source:

‘Unknown’ USV located near SEVASTOPOL, Ukraine 21 September 2022. (Source: NATO C-IED Center of Excellence reporting)

Back to the present: a mysterious find in Crimea

Fuzes identified as Russian UP 581 impact nose sensor fuze for FAB 500 SHN & FAB 500 SHL aerial bombs. (Source: NATO C-IED Center of Excellence reporting)

On 21 September one USV of an unknown model was located at Omega Bay, near the Russian Naval base in Sevastopol. Russian forces reportedly destroyed the device with a controlled detonation in the Black Sea after conducting technical exploitation. At that time this was the first spotting recorded of such a device. Only after that, when the surprise factor was achieved, Ukraine unveiled a crowdfunding campaign to build up to 100 new USVs. According to the information released in UNITED 24, the devices are 5,5 metres long, full weight up to 1000 kg, with a main charge up to 200 kg. The stated range is 800 km, with 400 km operational radius, and 60 hours of autonomy. It has 3 different navigation methods: automatic GNSS, inertial and visual. One naval drone is worth $250.000, including a ground-based, autonomous control station, a transportation and storage system, and a data processing center.

UP 581 impact nose sensor fuze for FAB 500 SHN & FAB 500 SHL aerial bombs. (Source: NATO C-IED Center of Excellence reporting)

From different footage and images published in open sources, the device is a boat hull, probably manufactured in fiberglass or aluminium, about 5-6 meters long. It has a FLIR EO/IR FMV camera, with a Starlink antenna providing beyond-line-of-sight (BLOS) communication via satellite to ensure accurate GPS navigation and reduced radio frequency signature, and a laser rangefinder. It has rudderless jet propulsión, similar to the SeaDoo 155/260 jetski with the ROTAX 4-TEC 1503 HO engine. As a firing switch, it has 2 UP 581 nose sensor fuzes located at the prow of the vessel, commonly used in Russian FAB 500 aerial bombs. Due to the dimensions of the FAB 500 and the USV, it is not possible that the aerial bomb itself can be the main charge. Taking into account the size (3,55mx 1,20m) and weight (maximun about 820kg) of the jetski equipped with the same engine, a compromise between fuel and main charge must be done, so potentially 200 kg as main charge (either explosives or warhead) could be feasible. Also, the rest of the technical features stated in UNITED 24 are likely over-dimensioned. Due to the fact that the USV of Omega bay was captured, did the devices lack a self- destruction capability or did it not work properly?

Analysis from the October 29 attack.

According to Russian statements, “the attack involved nine unmanned aerial vehicles and seven autonomous maritime drones. Four marine unmanned vehicles were annihilated by shipborne weapons and maritime aviation of the Black Sea Fleet, and three more were destroyed on the inner roadstead”. Taking this Information as an assumption, UKR USVs succeeded in breaching the port defences and Russian TTPs, allegedly damaging 2 surface units. At the same time, the counter measures put in place had some degree of success.

Positive Identification (PID) of the RUS Admiral Makarov frigate from IR imagery from the UKR USV.
(Source: )

Frame of the imagery from UKR USV. (Source:

Sevastopol Russian naval station ́s defenses after the find of 21 September. (Source:

The Ukrainian Armed Forces have since released footage purportedly from aboard several USVs used in the attack. The videos show the purported attack run on a missile frigate and a minesweeper, also barely missing a small harbor patrol boat, and Russian forces engaging the USVs with machine-gun fire. Finally various explosions are revealed both from Ukrainian and Russian footage. The images switch from electro optical (EO) to infrared (IR), showing the process to positive identification (PID) of the frigate and and the minesweeper, the counterefforts from the air (machine-gun fire from a MI-8) and the sea (gun fire from the frigate).

It is worth to mention that after the 21 September ‘Find’, the Russian Navy has improved their port defenses at Sevastopol and even redeployed their Kilo class submarines from Sevastopol to Novorossiysk. But despite dolphins (best suited to counter combat divers), weapons, physical barriers, sensors, and patrolling vessels, tactical surprise was achieved by the attacking party.

These defensive measures are additional to the adaptation of Russian TTPs after the sinking of the Moksva Cruiser on 14 April, hit by 2 Ukrainian-made R-360 Neptune anti-ship missiles. Since then, Russia had to take into account the Ukrainian Anti-Access Area Denial (A2AD) bubble, that in the end led to the Russian withdrawal from “Snake Island” on 30 Jun.

So what?

USV and UCAV (Unmaned Combat Air Vehicle) strikes show that Russian warships are not safe even in their ports. Not even submarines are spared from this threat.

From a targeting perspective, for sure Ukraine cannot aspire to sink every Russian vessel or completely destroy every facility or installation they engage, but they have managed to flip the coin and be back in the ring. Due to the payload of these USVs, it is very difficult for them to sink a large surface combatant, but if used in swarm tactics, they can cause heavy damage to neutralize these ships. In other words, we should not focus only on the physical or functional damage caused to the equipment and facilities targeted by Ukraine, but finally on the systemic effects achieved with such actions.

Satellite imagery from Sevastopol RUS Navy station.

Russian naval bases on the Black Sea coast. (Map by Nikolai Korolev)

Asymmetric warfare TTPs in conventional warfare are here to stay. Since 24 February when the Russian Navy was almighty in the Black Sea, it is not yet operationally cornered but their naval stations can be kinetically engaged, their combatant units with Kalibr cruise missiles must make the most of their stand-off capability to target Ukraine in depth, and an amphibious assault is simply chimeric.

The combination of Anti-Access/Area Denial (A2AD) capability for vessels off shore and the asymmetric threat from USVs (even combined with UCAVs), capabilities progressively obtained by Ukraine have put in check the control of the Black Sea by Russian Navy.

Commercial weapons systems vs improvised weapon systems: breaking the paradigm

As the European Defense Agency States: “Improvised Explosive Devices (IEDs) continue to be the weapon of choice for adversary networks and this phenomenon is likely to continue for decades, either with the IED as the only threat or combined with others within a hybrid complex scenario”. To this extent, many politicians, journalists and even military personnel believe in the paradigm that associates IEDs with terrorism. Although is absolutely true that for decades the IED has been (and is still) the weapon of choice of multiple terrorist organizations, resurgence of the conventional warfare conflict allows state actors/militaries to employ IEDs, both in conventional and asymmetric TTPs. Consequently this taboo must be broken.

Last, we could argue about the IED use as a licit weapon system that might cause human collateral damage by armies and navies, or if the Ukrainian USVs are ‘improvised’ or ‘commercial’… but for sure ‘state of the art’ USVs employed with asymmetric TTPs in conventional warfare has revealed itself as a game changer in the Black Sea. ■

This article does not represent the opinion of any national or multinational organisation; its whole content should only be considered as the opinion of the author. As all the information has been obtained from open sources, potential mistakes could have been made during the research process. Please feel free to send your comments, corrections and inputs to the author, they will be highly appreciated.



Chief Warrant Officer (CWO) Angel Peiro entered the Spanish WO Army Military Academy in 1993. Graduated in 1996, as a Military Engineer WO he has commanded sapper and recce units. Since 2002 he has been assigned to different posts as an all sources intelligence analyst. He has military qualifications as airborne, riverine combat diver, military intelligence, joint targeting and C-IED Technical Exploitation. He has operational experience in the Balkans, Iraq, Lebanon, Libya and Mali. He is currently posted in NATO as a military C-IED analyst.


Download PDF: 69-77 Angel Peiro – USV IEDs IN THE BLACK SEA – WHEN THE IMPROVISED BECOMES STATE OF THE ART – Counter-IED Report Winter 2022-23