The US Military Borrows from Iran's 'Gray Ship' Tactics, Potentially Transferring Nearly 90 Million Barrels of Gulf Crude

June 17 – A Reuters investigation has found that amid rising tensions in the Strait of Hormuz and the threat of an Iranian blockade, the U.S. military has established an unconventional ship-to-ship (STS) crude oil transfer network to keep Gulf energy exports running. The operation started in early May 2026, with at least 116 oil tankers involved so far, moving roughly 90 million barrels of crude and petroleum products in total. It’s focused on international waters off the UAE’s Fujairah and near Oman’s Sohar port. Satellite images show a recent spike in tanker anchoring there, with up to 10 or more vessel groups operating at once at times. To avoid being tracked in sensitive areas, the ships turn off their AIS transponders and reduce visible signals—tactics similar to Iran’s long-standing sanction-evasion shipping methods, according to informants. The network relies on U.S. coordination for scheduling and surveillance support, including drones, helicopters, and maritime monitoring resources, though the Pentagon has not confirmed direct military involvement in loading and unloading. The U.S. Department of Defense stated Central Command forces are not part of the nearshore STS transfer operations. Gulf security remains tense: the Gulf of Oman recently saw unidentified attacks on oil tankers, leading to a peak in tanker activity in some areas. Analysts call this system "gray shipping," which uses temporary transfers and covert scheduling. While less efficient than normal Strait of Hormuz passages, it has become an emergency alternative to maintaining global crude flow amid geopolitical conflicts. Reuters estimates the network’s transfer volume is far lower than the pre-war 20 million barrels per day that typically passed through the Strait of Hormuz, so it’s viewed as an emergency backup rather than a long-term solution.