Since August, Russian oil tankers navigating the Bosporus Strait in Istanbul have increasingly adopted physical countermeasures, including netting, metal cages, and rubber tires, to defend against ongoing drone attacks originating from Ukraine. These measures are part of a broader effort to safeguard Russia’s vital energy exports amid an intensifying campaign by Kyiv targeting the so-called "shadow fleet" of tankers sustaining the Kremlin’s economic lifeline.
Maritime analysts monitoring the Black Sea have identified at least 60 vessels outfitted with these improvised anti-drone defenses during their passages through the Bosporus. The modifications focus on protecting critical ship components, such as engines and rudders, with netting and “cope cages” — metal frames initially deployed by Russian and Ukrainian ground forces to counter low-cost, remotely piloted first-person-view (FPV) drones that evade traditional air-defense systems. The use of such countermeasures has parallels with Israeli military tactics against FPV drones used by Hezbollah and Gaza militants.
Security observers note the similarity between the netting on the tankers and defensive measures seen in frontline Ukrainian cities. Eric Woods, an independent analyst specializing in Russia, described the appearance of the vessels as evocative of battlefield defenses in urban combat zones. Ship spotter Yoruk Isik, who leads a consulting firm in Istanbul, characterized the protective efforts as a “makeshift” response highlighting Russia’s diminished control over the Black Sea maritime environment. He emphasized that the Russian navy’s vulnerability threatens the country’s ability to generate foreign currency through oil exports.
Ukraine’s targeting of the shadow fleet represents a strategic approach to weaken Russia’s financial infrastructure by focusing on aging tankers often insured and underwritten through Russian state-backed banks, circumventing international shipping norms. Ukraine’s drone forces commander stated in September that around 300 shadow-fleet vessels had been disabled since July, though this figure has not been independently verified. The intensified attacks began in 2025, in part as leverage during peace negotiation efforts under the previous U.S. administration.
Ukraine has also deployed uncrewed sea drones that navigate the water surface to strike vessels, but the recent adoption of anti-drone nets by Russia indicates a shift towards defending against aerial FPV drones capable of longer-range attacks. This escalation underscores the growing tactical significance of the Black Sea, which has seen increased Russian missile and drone strikes on Ukrainian grain-exporting ports, prompting retaliatory strikes by Ukraine to push Russian naval forces eastward.
The conflict’s maritime dimension has spilled over into neighboring NATO states. Romania and Bulgaria have attributed repeated drone attacks on ships near their waters to Russia, highlighting the heightened risks to regional security and trade. These disruptions have further contributed to global economic pressures, including spikes in wheat prices owing to Russian strikes on Ukrainian grain exports.
The use of low-cost drones and countermeasures in maritime conflict is also evident beyond Eastern Europe. Iran’s deployment of similar unmanned systems against U.S. and allied forces in the Strait of Hormuz has exacerbated energy supply concerns this year. Experts predict that physical anti-drone defenses like nets and cages will become a widespread and cost-effective method to protect vessels globally against unmanned aerial threats.