Ukraine’s nautical drone swarms revolutionize naval warfare

The eyes of the world’s naval powers are on Ukraine: how is it that a country with only a handful of small warships is defeating mighty Russia in the Black Sea? With minimal investment, the Armed Forces of Ukraine claim to have disabled a third of the Kremlin’s fleet in the Black Sea. At least 12 ships and one submarine have been destroyed or damaged, cases for which EL PAÍS has found visual evidence, although Kyiv raises the number to 25. The most recent successful attacks this month sank the corvette Ivanovets and the landing ship Tsezar Kunikov with a tactic coordinated to the millimeter with swarms of nautical drones.

The Ivanovets was, along with the frigate Admiral Makarov, the Russian fleet’s flagship in the Black Sea as of April 2022, when a Neptune anti-ship missile sank the cruiser Moskva. The Neptunes are Ukrainian-made but their numbers are limited, the Defense Ministry has admitted, because of the complexity of producing them in wartime due to the large infrastructure required and the threat of Russian shelling of the production center. The Ukrainian military has prioritized reconverting the few units it has into medium-range missiles against ground targets in Crimea, which was illegally annexed by the Kremlin in 2014 and serves as the base of its Black Sea fleet. Much cheaper and easier to produce are the marine drone bombs deployed against the Ivanovets and the Tsezar Kunikov.

Between the beginning of the invasion in February 2022 and the autumn of 2023, the Ukrainian budget for the production of its drones, in secret underground locations, stood at around €30 million ($32.3 million). This figure was provided by NATO sources to Lee Willett, a researcher at the Royal Swedish Society of Naval Sciences, for an analysis published in November 2023. That is less than half the cost of building the Ivanovets, according to the Ukraine Defense Ministry’s GUR intelligence directorate.

Sidharth Kaushal, a researcher at the UK Royal United Services Institute, explained in a study this month how incredibly affordable it is to assemble these drones: “They are easy to build, equipped with electro-optical and infrared sensors, a Starlink [satellite communication system] antenna and other commercial components such as pleasure craft engines.”

Experts stress that Ukraine is not the first to develop marine drones, even low-cost and almost artisanal ones. Yemen’s Houthi rebels, for example, attacked the Saudi frigate Al-Madinah in 2017. But the Ukrainians are pioneers in the systematic and effective use of these devices, according to a study last October by the U.S. RAND center.

Ukraine’s first attack with nautical drone bombs was launched in October 2022. It was a combined strike with unmanned aerial vehicles against two frigates (including the Admiral Makarov) and a minesweeper in Sevastopol Bay. All three ships were damaged, but were able to be repaired. The level of effectiveness on the part of Ukrainian forces since then has increased dramatically. The sinking of the Ivanovets on February 1 and the Tsezar Kunikov on February 14 are proof of this.

Both attacks followed the same parameters. Swarms of at least six Magura drones, controlled from 300 kilometers (186 miles) away by GUR special forces, were launched against the two ships. In both cases they were anchored in enclosed bays, a short distance from shore. Both RAND analysts and Kaushal agree that unmanned devices are most effective when they are not deployed against targets in the open sea, where vessels have more maneuverability and where the choppier water destabilizes the drones. The Tsezar Kunikov and the Ivanovets were initially static targets with part of their escape routes closed off by land.

A pack of wolves

Defense Express, a Ukrainian media outlet specializing in military analysis, detailed the tactics of these Magura swarms this February. Videos provided by the GUR of the two attacks show the operation, with images recorded by the drones, evoking the teamwork of a pack of wolves stalking its prey.

The drones first target the rudder, so that the ship loses its ability to maneuver. All the crew can do at this point is attempt to bring down the unmanned vehicles with onboard machine guns. But the Magura can cruise at 40 kilometers per hour (25mph) and, as can be seen in the videos, the pilots do not follow fixed trajectories. When a drone hits the hull of the ship, the following drones will target the same spot, as they inflict more damage where a breach has already been opened. Furthermore, as Defense Express indicated, the Ukrainians aim for the points where they know the ship’s ammunition is stored, causing a bigger explosion.

Kyiv has managed to force most of the Russian fleet to withdraw from Crimea to Novorossiysk, on the Russian coast of Krasnodar province, 550 kilometers (340 miles) from unoccupied Ukraine. Despite this, the Security Service of Ukraine (SBU) managed to hit the landing ship Olenegorskiy Gornyak in the port of Novorossiysk in August 2023 using nautical drones. It was not specified which device was used, but the SBU operates two models christened Cossack Mamay and Sea Baby. The latter, which has rocket launchers, was successfully used in July 2023 to attack the Kerch Bridge, which connects Crimea with Russia. Cossack Mamay is, according to Ukrainian experts, the fastest military vehicle in service in the Black Sea, with a top speed of 110 kilometers per hour (68mph).

Kaushal warns in his study that it is too early to say how long Ukraine will hold the advantage in terms of nautical drones, because military technology is advancing rapidly, both in offensive and defensive strategy. In World War II, multiple anti-submarine systems were quickly and successfully developed, Kaushal recalls. And the invasion of Ukraine has shown that the Russian state is capable of progress. In the first year of the war, the Ukrainians were far superior in the use of bomb drones and commercial aerial UAVs adapted for combat. Russia now has clear dominance in this area.

The RUSI researcher concedes that nautical drones will always have the surprise factor in their favor, because they are very difficult for radar to detect. Ukraine has so far managed to keep Russian ships away from its waters, open a new maritime export route and reduce the threat of Kalibr cruise missile launches by the Kremlin’s fleet.

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