Covert tanker transfers moved an estimated 90 million barrels of oil
US-backed operation helped bypass Strait of Hormuz shipping disruptions
At least 92 vessels participated as Gulf energy exports continued flowing
The US military has been overseeing a covert operation of ship-to-ship oil transfers off the coast of the United Arab Emirates and Oman since early May, deploying drones and helicopters to guide tankers around Iran's blockade of the Strait of Hormuz and keep Gulf energy exports reaching international markets, according to an exclusive Reuters investigation citing 11 people familiar with the operation.
The technique, long used by Iran itself to evade sanctions, involves tankers sailing to a meeting point before the strait, staggering their departures so they remain 3,000 to 4,000 metres apart with transponders switched off and lights dimmed. The news agency reported that once they clear the zone Iran has designated under its control, the tankers pull alongside Very Large Crude Carriers to transfer oil over 24 to 40 hours, before sailing back empty while the loaded VLCCs continue on to international buyers.
At least 92 ships have taken part since the operation began, with satellite imagery on June 11 showing 17 pairs of vessels conducting simultaneous transfers at the two main sites — one off Fujairah in the UAE, the other off Oman's port of Sohar.
Reuters estimated, based on tanker carrying capacities, that at least 90 million barrels of crude and petroleum products may have moved through the network since early May — still a fraction of the roughly 20 million barrels that transited the strait daily before the war, but a meaningful lifeline for Gulf producers nonetheless.
Apache Helicopter Downing Linked to the Operation
The operation took on added significance after an Apache helicopter was shot down by Iran on June 9, an incident that triggered retaliatory US bombings. Four sources, including a former US official, told Reuters that the helicopter had been involved in the mission. Satellite imagery reviewed by the agency showed six pairs of tanker ships clustered off Sohar on the day of the downing. A US defence official said no Central Command forces were taking part in offshore ship-to-ship transfers, and officials confirmed both helicopter crew members were rescued by a drone boat.
Sources informed Reuters that the US has supported the operation through aerial surveillance, compliance screening and monitoring rather than direct naval escort, with no indication that US military personnel were physically involved in the transfers. Operators seeking access must undergo a compliance review through the US Navy's Naval Cooperation and Guidance for Shipping office in Bahrain, submitting geospatial tracking histories, beneficial ownership disclosures and cargo documentation before being assigned transit windows.
The UAE's state oil company ADNOC has been among the most active participants alongside the Kuwait Oil Tanker Company. One Kuwaiti vessel transferred roughly 2.3 million barrels off Sohar on 6 June; the receiving ship was later spotted off India's southwest coast bound for China.
