Key Takeaways
A multi-day halt in oil loadings from Iran’s primary export terminal is now believed to be caused by an oil spill, challenging initial assumptions of a blockade-related stoppage.
A complete halt in crude oil loadings from Iran's Kharg Island has extended for at least eight days, a disruption shipping monitors attribute to a potential oil spill rather than the ongoing US naval blockade in the region.
"There’s been a multi-day pause in the loading of big, ocean-going tankers from the facility," Samir Madani, co-founder of TankerTrackers.com, said, noting his firm observed no large-tanker cargo collections on Friday.
Maritime intelligence firm Windward corroborates the stoppage, reporting no confirmed crude departures from Kharg Island since May 7. The firm’s analysis of satellite imagery shows all loading terminals were empty for three consecutive days, despite approximately 20 tankers with a combined carrying capacity of more than 25 million barrels remaining staged in holding areas near the island.
The disruption at Iran's most critical export terminal tightens the global oil supply at a time when a US blockade is already targeting the nation's shipping. The incident highlights the vulnerability of Iran's export infrastructure and its growing reliance on a complex, covert system to move its crude.
The loading halt at Kharg Island comes as Iran re-engineers its maritime logistics in response to intense US pressure. According to Windward, significant portions of the Strait of Hormuz are "increasingly functioning as controlled maritime operating zones" rather than normal commercial corridors. This involves a growing network of "dark" tankers—vessels with their AIS transponders disabled—anchoring in protected Iranian waters near Larak and Qeshm islands.
These areas serve as staging grounds for covert ship-to-ship transfers, allowing Iran to blend and re-label its crude away from prying eyes. The strategy is supported by an intensified presence of Islamic Revolutionary Guard Corps (IRGC) patrol craft, which escort and surveil the stationary commercial vessels, effectively creating a shielded ecosystem for sanctions evasion.
The US blockade, which began in mid-April and has intercepted over 70 vessels, has forced the Iranian fleet and its customers to employ a range of deceptive tactics. According to a New York Times analysis of shipping data, there was a 600 percent increase in ships using such tactics between April 19 and May 3.
Vessels are routinely turning off location trackers, "spoofing" their positions to appear in different locations, and taking uncommon, longer routes to Asia. The Iran-flagged tanker Huge, for instance, sailed with its tracker off and transited Indonesia’s Lombok Strait, a less common route than the Strait of Malacca, to reduce visibility on its way to China. This cat-and-mouse game demonstrates the lengths shippers will go to move Iranian oil, even as the physical infrastructure at the source shows signs of strain.
The dual pressures of direct operational disruptions, like the suspected Kharg Island spill, and the overarching strategic blockade are severely testing Iran's export capabilities. While Tehran has developed a sophisticated system to circumvent sanctions, the reliance on aging infrastructure and a shadow fleet creates multiple points of failure that can impact global energy markets without warning.
This article is for informational purposes only and does not constitute investment advice.
