How the Shadow Fleet Spoofs Location Data to Evade Global Oil Sanctions

For global oil sanctions to function, the physical location of the vessels carrying the crude must be verifiable. That condition no longer holds. A parallel maritime infrastructure has emerged to transport sanctioned petroleum, operating entirely outside standard insurance markets and regulatory oversight.[3]

This network, commonly known as the shadow fleet, relies on aging hulls and sophisticated digital deception to move millions of barrels of oil daily. By manipulating mandatory tracking systems and transferring cargo in open waters, these vessels effectively sever the link between the origin of the oil and its final destination.[3]

The scale of this parallel market is substantial. According to S&P Global, the shadow fleet now comprises 978 tankers with a combined capacity of 127 million deadweight tonnage. That represents approximately 18.5% of the global oil tanker fleet, a fraction that has grown steadily since the Group of 7 implemented a $60 per barrel price cap on Russian crude in December 2022.[1]

The primary mechanism for evasion is the manipulation of the Automatic Identification System (AIS), the tracking transponders that all commercial vessels are required to operate. While turning off AIS—going "dark"—was the initial tactic, operators have shifted to active spoofing to avoid drawing immediate suspicion.

Lloyd's List Intelligence recorded a significant uptick in spoofing-related incidents throughout 2025 and into 2026. Rather than simply disappearing from radar, vessels transmit falsified positional data. A tanker might broadcast that it is sailing a normal route in the Red Sea while it is actually loading sanctioned crude at an Iranian port or conducting a transfer in the Gulf of Oman.

"What may look like a routine AIS anomaly on the surface, could be a calculated deception," Lloyd's List analysts noted in August 2026. "From falsified positions, to cloned MMSI numbers, AIS spoofing is no longer on the fringes - it's becoming a daily operational hazard."

Once loaded, the oil is rarely delivered directly to its buyer. Instead, it is moved via ship-to-ship (STS) transfers. Two vessels meet in international waters, connect hoses, and pump crude from one hull to the other, often blending it with oil from other jurisdictions.

These transfers frequently occur in designated hotspots, such as the waters off Greece, Spain, and the Gulf of Oman. By moving the cargo to a "clean" vessel that has not docked at a sanctioned port, the origin of the oil is obfuscated, allowing it to be sold to refineries in India or China without triggering compliance alarms.[2]

The Kyiv School of Economics reported that in January 2025 alone, 192 shadow tankers carrying crude oil and petroleum products either left Russian ports or lifted cargo after STS transfers. During that month, 86% of Russia's crude oil exports were transported by this fleet, demonstrating the system's efficiency.[2]

To further complicate enforcement, these vessels engage in "flag hopping." Tankers frequently change their country of registration to jurisdictions with minimal regulatory oversight, such as Panama, Barbados, or Eswatini, making it difficult for authorities to track ownership.

Researchers at Duke University highlight that these flags of convenience lack the ability or the political will to enforce G7 sanctions. When one registry tightens its rules—as Panama did in late 2025 by refusing tankers over 15 years old—the vessels simply re-register elsewhere.

The physical condition of the fleet presents a separate, acute risk. The average age of a shadow tanker is 20 years, a point at which conventional vessels are typically sold for scrap due to metal fatigue and outdated safety systems.[1]

Because these ships operate outside the International Group of Protection and Indemnity (P&I) Clubs, they lack standard maritime insurance. If a 20-year-old hull fractures during a mid-ocean transfer, the coastal state nearest the spill would likely bear the entire cost of the environmental cleanup.[3]

"When people talk about sanctions, a lot of times they don't understand what side effects you would have. [Those] could really [be] devastating," Jan Dieleman, head of shipping at Cargill, told a maritime panel in June 2025.[1]

Data from the classification society DNV underscores this vulnerability, showing that 52% of all ship incidents in 2024 involved vessels aged 20 years or older, a sharp increase from previous decades.[1]

Western regulators are attempting to close these loopholes. The European Union and the US Treasury's Office of Foreign Assets Control have begun sanctioning individual vessels and the opaque corporate entities that manage them, aiming to restrict their access to global ports.[2][3]

Yet the fleet continues to adapt. When specific tankers are blacklisted, they are often retired and replaced by newly purchased second-hand vessels, keeping the overall transport capacity stable despite the regulatory pressure.[2]

The persistence of this infrastructure indicates a structural shift in global shipping. So long as the financial incentives of the risk premium outweigh the penalties of detection, the parallel market will continue to refine its methods of evasion.[3]