First Sanctioned Tankers Breach U.S. Blockade with Five Million Barrels of Iranian Crude

Three sanctioned Iranian tankers exit the Gulf despite the U.S. naval blockade. Tracking data shows the vessels heading toward Singapore for STS transfers.

By: AXL Media

Published: Apr 17, 2026, 9:09 AM EDT

Source: Information for this report was sourced from AFP

A Calculated Breach of the Maritime Siege

In a significant challenge to Washington’s newly enforced maritime restrictions, three Iranian-flagged tankers carrying a combined five million barrels of crude oil navigated the Strait of Hormuz on Wednesday. According to data from the tracking firm Kpler, the vessels—Deep Sea, Sonia I, and Diona—departed from Iran’s primary terminal at Kharg Island after loading their cargoes between April 2 and April 9. This movement marks the first successful export of Iranian crude since the U.S. naval blockade officially took effect on Monday, April 13, at 10:00 a.m. ET, following the failure of diplomatic negotiations in Islamabad.

The Logistics of the Shadow Fleet

The tankers involved in the transit are long-standing members of what maritime analysts describe as Iran’s "ghost fleet," a network of aging vessels that utilize deceptive practices to bypass international oversight. To avoid detection by the U.S. Navy’s 5th Fleet, the ships reportedly deactivated their Automatic Identification System (AIS) transponders weeks before the transit, a tactic frequently used to mask vessel location and trajectory. Kpler utilized high-resolution satellite imagery to verify the crossing, confirming that the tankers were fully laden and moving eastward toward the Indian Ocean, bypassing the clusters of loitering commercial ships that have remained stationary due to the ongoing conflict.

Ship-to-Ship Transfers and the Singapore Hub

While the final destinations of the Deep Sea, Sonia I, and Diona remain unlisted, historical tracking data suggests they are bound for anchorage areas near Singapore and the Malaysian coast. This region has emerged as a critical "laundering hub" where Iranian crude is transferred ship-to-ship (STS) to third-party tankers. According to reports from Global Fishing Watch, these transfers effectively obscure the oil's origin before it is delivered to independent refineries in northern China, specifically the ports of Yantai and Dongjiakou. In March alone, at least 37 Iran-linked tankers conducted similar maneuvers, moving an estimated 62 million barrels despite the regional hostilities.