March 2025 Iran Tanker Tracker

As the maritime industry gathered for Singapore Maritime Week 2025, one of the industry's most important annual events, participants grappled with a central concern: the intensifying threat posed by the Iranian-backed ghost fleet. Against a backdrop of rising geopolitical tension, sanctions enforcement, and growing environmental risk, the week's discussions reflected the urgency of safeguarding the integrity of global shipping.

A highlight of the week was a keynote speech by Singapore's Senior Minister Lee Hsien Loong, who underscored Singapore's enduring commitment to free and secure maritime trade. He acknowledged the challenges posed by today's strategic environment and warned about “Choppy waters ahead,” and that “it is a different world today. Attitudes towards trade have changed. Patterns of trade flows are shifting, too.  Minister Lee emphasized the importance of rule-based maritime order and Singapore's role as a trusted maritime hub: “Singapore will continue to support a multilateral rules-based order, international co-operation and interdependence.”

At the Lloyd's List Maritime Outlook Forum, Professor Robert Beckman of the National University of Singapore detailed legal avenues coastal states can use to confront illicit activity. He argued that countries bordering critical chokepoints- like the Singapore and Malacca Straits- have both the right and obligation to investigate and interdict dark fleet activity. This is especially relevant as Iranian tankers increasingly exploit these waters to conduct illicit ship-to-ship (STS), often just beyond regulatory oversight.

This trend continued throughout the month of March, with the majority of Iran’s oil exports headed to China.

*figures to be updated over the following weeks.

Concerns about the environmental threat posed by these illicit tankers were reinforced by the latest Oil Tanker Spill Statistics 2024 from the International Tanker Owners Pollution Federation (ITOPF). While overall spill numbers remain relatively low, six large spills (over 700 tonnes) were recorded last year. Several involved aging, unclassified tankers operating outside traditional oversight, many believed to be part of the fleet moving sanctioned Iranian oil near critical Southeast Asian shipping lanes. incidents involving older tankers operating outside regular classification society oversight. 

The risk of a catastrophic spill continues to grow, paralleling the ongoing expansion of Iran’s sanctions evasion network. On March 14, 2025, OFAC announced sanctions on a Singapore-based company and multiple tugboats for facilitating ship-to-ship (STS) transfers of Iranian crude in Indonesia’s Nipa Anchorage. This reflects a broader trend in which local service providers in Singapore and Malaysia enable Iranian oil to change hands under the radar. 

Then, for the first time, OFAC sanctioned a “teapot” oil refinery in China, for purchasing and refining hundreds of millions of dollars’ worth of Iranian crude oil, including from vessels linked to the Foreign Terrorist Organization, Ansarallah (Houthis) and the Iranian Ministry of Defense of Armed Forces Logistics (MODAFL).

“Teapot refinery purchases of Iranian oil provide the primary economic lifeline for the Iranian regime, the world’s leading state sponsor of terror,” said Secretary of the Treasury Scott Bessent.

Further evidence of tightening enforcement came from the US Justice Department, which filed a civil forfeiture complaint for cargo of Iranian-origin oil that had been transferred via a number of illicit STS operations in Malaysian waters off Pulau Kukup and eventually ended up in a facility in Croatia. The case illustrates how shadow fleet activity in Southeast Asia has direct ramifications across global oil markets. 

As the International Maritime Organization (IMO) Assembly's December 2023 resolution A.1192(33) emphasized, international cooperation is essential to combat these challenges. That resolution called for greater transparency in shipping registries and improved coordination among coastal states. The ongoing work of the IMO Legal Committee on fraudulent ship registration and the push by member states for stronger enforcement mechanisms are welcome developments.

With Iranian oil continuing to flow via deceptive STS practices and opaque registries, the maritime industry should expect more sanctions designations, increased monitoring, and deeper scrutiny. But sanctions alone won’t be enough. Only through robust regional coordination and global enforcement can the threats posed by the dark fleet—to global security, the environment, and maritime law—be meaningfully contained.