British Royal Marines successfully boarded and seized a Russian tanker, the CMR Smyrtos, in the English Channel in a carefully coordinated operation that marked the first UK-led interdiction of a sanctioned Russian vessel. The mission took place overnight on June 25-26, involving a combination of helicopter insertions, naval support, and extensive surveillance.

The 243-meter tanker had departed from Ust-Luga, a major oil terminal near St Petersburg, on June 5 before navigating westward through the Baltic Sea. Notably, it avoided Swedish territorial waters by rerouting south of the island of Bornholm, where authorities have increased enforcement against so-called “shadow fleet” vessels. The tanker later entered British waters around midday on Saturday and maintained a steady speed before adjusting course near the Isle of Wight toward Weymouth under cover of darkness.

The seizure operation was launched just after midnight, with CH-47 Chinook helicopters inserting Royal Marine commandos onto the vessel as it moved through one of the busiest shipping lanes globally. The boarding was executed swiftly and with minimal disruption to the vessel’s course. Following the takeover, the tanker was escorted to an anchorage off the Isle of Portland, arriving early Sunday morning.

The task force included 40 commandos from 42 Commando’s Juliet Company, a unit specialized in maritime interdiction and trained for close-quarters combat in confined and complex ship environments. The operation was supported by the frigate HMS Sutherland, the minehunter HMS Ledbury, and an RAF P-8 surveillance aircraft, alongside other air assets such as Merlin Mk4 and Wildcat helicopters.

Lieutenant Colonel Tom Quinn, commanding officer of 42 Commando, described the boarding team as “sizeable” and emphasized that intercepting vessels of this nature is routine for the UK Commando Force, though fast-roping onto a moving tanker at night presented unique challenges. The operation required rapid seizure of the bridge to prevent crew interference with ship controls or destruction of evidence. Once secured, the command team maneuvered through the vessel’s engine room and cargo control areas to disable the crew’s ability to maneuver or tamper with the ship’s systems.

Security concerns have grown around the presence of armed guards on sanctioned Russian vessels, often personnel linked to mercenary groups like Wagner, who have combat experience in Syria and Ukraine. While the Smyrtos did not have armed guards at the time of boarding, Quinn acknowledged that future operations must account for potential resistance, although he indicated that such guards have generally been unarmed and unlikely to engage in combat.

Following the seizure, the Royal Navy and National Crime Agency (NCA) teams boarded the tanker to conduct an extensive search for evidence including logs, documents, and electronic records. These materials are critical to tracing the vessel’s ownership, cargo details, and its role within the network facilitating Russian oil transport despite international sanctions. The 25 crew members, representing various nationalities, were taken into the care of the NCA.

This operation is considered a significant escalation in the UK’s enforcement efforts against Russia’s shadow shipping fleet. Since March, British forces have been authorized to halt, board, and detain sanctioned Russian vessels in UK waters, but this is the first instance in which Britain independently led such a seizure, having previously supported allied interdictions. Commanders exercised discretion before acting, and Quinn noted that the specific circumstances of the Smyrtos met the criteria to proceed with the operation.