How the US Used Secret Ship-to-Ship Transfers to Bypass Hormuz Blockade

As the Middle East crisis choked one of the world’s most vital energy arteries, the United States deployed a covert strategy to prevent a total global energy collapse. By adopting tactics similar to those used for sanctions evasion, the US military has orchestrated a massive offshore transfer operation to keep Gulf crude moving despite Iran's blockade of the Strait of Hormuz.

The "Shadow" Logistics: Ship-to-Ship Transfers

To circumvent the blockade, the US military implemented a sophisticated ship-to-ship (STS) transfer system. Rather than using traditional naval escorts, the US military focused on aerial surveillance, compliance monitoring, and logistical oversight.

The operation, which began in early May, utilizes a "hub-and-spoke" model. Smaller tankers navigate the high-risk Strait of Hormuz before meeting much larger Very Large Crude Carriers (VLCCs) at designated offshore hubs. These primary transfer points are located at Fujairah in the United Arab Emirates and near the port of Sohar in Oman. Once the smaller vessels pull alongside the VLCCs, the oil transfer process takes anywhere from 24 to 40 hours to complete.

Operational Stealth and Military Oversight

To avoid detection and mitigate the risk of Iranian interference, the vessels follow strict protocols designed for stealth. Tankers stagger their departures to maintain a distance of 3,000 to 4,000 metres from one another. During transit, ships are reportedly required to switch off their transponders and dim their lights to remain inconspicuous.

The US Navy’s Naval Cooperation and Guidance for Shipping office in Bahrain manages the process. Shipping companies must undergo rigorous compliance checks before being assigned specific transit slots. This system has involved at least 116 vessels since the operation commenced. At its peak on June 11, satellite imagery revealed 17 pairs of ships conducting simultaneous transfers across the two hubs.

Scale of Impact and Global Energy Risks

While the operation is massive in scale, it remains a fraction of normal volumes. Reuters estimates that at least 90 million barrels of crude oil and petroleum products have moved through this offshore network since early May. While significant, this is a small portion of the roughly 20 million barrels that typically pass through the Strait of Hormuz daily.

The disruption to the Strait—which normally carries one-fifth of global oil consumption—has created one of the largest energy supply shocks in history, driving global inflation. Furthermore, the covert nature of these transfers increases maritime risks. Industry officials have warned that traveling at high speeds in the dark without lights significantly raises the probability of vessel collisions.

Key Takeaways