Iran's Ghost Fleet: Secret Tankers Shift Oil at Sea to China

A network of aging tankers often described as Iran's 'ghost fleet' has continued moving Iranian crude toward China using ship-to-ship transfers, AIS disruption and frequent identity changes to obscure cargo origins. U.S. enforcement measures and international scrutiny have struggled to fully stem these maritime flows.

Investigations combining satellite imagery and vessel-tracking data show patterns of vessels disabling automatic identification systems (AIS), reflagging or renaming, and conducting multiple open-water STS operations in Southeast Asian anchorage zones. Monitoring groups reported concentrated activity near established holding areas such as the Eastern Outer Port Limits and other regional hotspots where transfers and re-exports facilitate delivery to refiners in China.

While global oil markets have so far absorbed much of the supply, the opacity introduced by these practices raises insurance and freight costs and adds an uncertainty premium to some crude streams. Traders and risk managers have adjusted exposures to account for potential enforcement actions, and insurers have increasingly scrutinized vessels with suspect histories, which can elevate logistics costs and complicate trading flows.

In the broader economic and political context, these shadow shipping practices enable Tehran to generate revenue despite sanctions, while exposing shortcomings in maritime governance and the international insurance framework. Official advisories and financial-crime units have highlighted the role of opaque ownership structures and maritime loopholes that facilitate sanctions evasion. The persistence of such flows complicates diplomatic and enforcement strategies aimed at cutting off regime revenue.

Market analysts say tighter international coordination, enhanced satellite and AIS monitoring, and targeted pressure on intermediary entities could reduce the effectiveness of the ghost fleet over time. However, absent rapid policy shifts, elevated risk premia in shipping and potential episodic price volatility tied to regional incidents remain plausible near-term outcomes.