Merchant Ships Turn to Drone Cages and Nets as Black Sea Attacks Escalate

Merchant ships crossing the Black Sea are adding improvised barriers as attacks on commercial shipping and port infrastructure intensify. Drones struck cargo ships off Romania and Bulgaria on 5 and 6 October 2026, according to Ukrainian and Bulgarian officials. Two vessels sank, and crew members were killed or reported missing.

The danger goes beyond drone strikes. The US Maritime Administration has warned that electronic-warfare interference with missile and drone guidance systems raises the risk of commercial vessels being hit by mistake.

Bulgaria's prime minister said the attacks were driving up insurance costs, and industry reports vessel queues and rising crew costs. This has raised concerns about the security of food-supply routes and prompted ships to find new ways to protect their passage.

Crews Improvise Protection Against Drones

Some merchant ships are fitting steel frames and wire screens, known as 'cope cages', over their bridges and upper structures. They are intended to deflect drones or trigger detonation before impact.

The oil tankers Brisk and Integrator have been observed passing through the Bosphorus with these frames. Other vessels have added heavy wire netting or tyres to exposed hull sections. The Russian-flagged tanker Khrizopraz was seen with tyres fitted across its hull.

The Sierra Leone-flagged tanker Caruzo has also been observed carrying water-filled containers suspended around its stern. The containers are intended to absorb blast energy and shield areas such as engine compartments.

Maritime security analysts say these low-cost measures may reduce damage from smaller commercial quadcopters and light first-person view drones. But they offer limited protection against larger military-grade loitering munitions, such as the Shahed-136, or fast uncrewed boats carrying heavy explosive warheads.

Those weapons can carry payloads designed to penetrate structures, potentially overwhelming or bypassing light screens and netting.

Detection And Tracking Remain Difficult

The Shahed-136's low-altitude flight and small radar signature can make it difficult for standard ship radar to detect. Commercial systems may filter out small radar returns to reduce clutter. If a drone is detected at two to five kilometres, crews may have only seconds or minutes to react.

Ships rely on visual lookouts and sound as well as radar. Maintaining a full 360-degree watch is difficult, particularly at night or in poor weather. Turning off or limiting a ship's Automatic Identification System (AIS) broadcasts may make it harder to track, but does not guarantee concealment.

Attackers may use historical voyage data, satellite imagery and other sensors to estimate a vessel's position. Active radio or radar emissions may also expose a ship to weapons designed to home in on those signals.

Operators Urged To Combine Precautions

Maritime bodies recommend risk assessments, less predictable routes, strict visual and audible lookouts, rehearsed evasive manoeuvres and designated emergency refuges for crews above the waterline.

The EU Black Sea Security Strategy, unveiled in May 2025, aims to protect shipping corridors and critical infrastructure. The European Commission has supported 65 projects worth €200 million, while Romania and Bulgaria have developed plans for a joint maritime security hub with bases in Constanța and Varna.

The European Maritime Safety Agency also supplies satellite imagery to authorities in both countries. However, European Defence Agency report identifies remaining gaps in naval air and missile defence, long-range strike capabilities, munitions stockpiles and seabed protection.