Iran continues to export oil despite U.S. sanctions and a naval blockade, relying on a network of vessels and intermediaries as well as tactics designed to conceal identities and manipulate navigational data.
Tehran is currently exporting about 260,000 barrels a day, its lowest level of oil sales in six years, compared with roughly 1.67 million barrels a day before the war.
But the continued flow of exports, even at sharply reduced levels, underscores Tehran’s ability to circumvent restrictions on its oil trade.
As part of its campaign to pressure Iran, the United States has imposed a naval blockade on shipping to and from Iranian ports, with the aim of halting Iranian oil exports. The blockade includes monitoring and intercepting vessels attempting to transport oil from Iran, while shipping routes bound for non-Iranian ports remain outside its stated scope.
Vessels involved in the smuggling operation are using false documents and records in order to pass through the blockade imposed on Iran by the U.S. Navy. When stopped by patrolling U.S. vessels, the “shadow fleet” ships present information that launders the Iranian origins of their cargoes – and are thus usually allowed to pass through the cordon.
Tracking data reviewed by MBN show that some vessels have indeed used methods to conceal their identities and movements, including disabling their AIS transponders and manipulating location data.
Over several weeks, MBN reviewed dozens of satellite images and navigational records, documenting oil transfers off Iran’s coast in which cargoes were moved from Iranian tankers to other vessels that carried them to their final destinations.
The practice is known as a ship-to-ship, or STS, transfer.
U.S. sanctions have forced Iran for years to rely on such operations. Its tankers have carried crude to areas far from the Iranian coast, including the Strait of Malacca off Malaysia and Singapore, before transferring it to other vessels.
Urriolagoitia Miner, a former U.S. military intelligence official and an expert on counterterrorism financing, told MBN that Iranian oil “doesn’t get out through concealment alone; it is laundered at sea.”
Transferring a cargo from a sanctions-linked vessel to another ship with a clean record, he said, is intended to “erase its digital identity.”
Satellite images analyzed by MBN documented more than 30 ship-to-ship transfers involving Iranian tankers.
Most were concentrated in three locations. The most prominent was near the Iran-Iraq maritime border, close to Kharg Island, through which 90% of Iranian crude exports pass. About 15 other cases were documented off Larak Island, in the heart of the Strait of Hormuz, as well as in the Gulf of Jask off Iran’s southeastern coast.
The latter two locations are of particular strategic importance because they are overseen by three naval bases operated by Iran’s Islamic Revolutionary Guard Corps, providing a security umbrella for the tankers and smaller vessels used in the operations.
Miner said the Iranian government and the Revolutionary Guard were the main actors behind the operations, using the proceeds to finance the military budget and Tehran’s regional proxies. Behind that core network, he said, is another layer of intermediaries, including “financial warlords and marine equipment suppliers in East Asia,” who reap substantial profits from facilitating the operations.
Vessels used to smuggle Iranian oil are known collectively as the “shadow fleet.” According to estimates by Windward, a maritime data and tracking company, Iranian oil tankers have routinely disabled their tracking systems, causing their positions to disappear, particularly when they are involved in transferring cargo to other vessels.
But how are the vessels that make up Iran’s “shadow fleet” able to circumvent the blockade? Miner said the “shadow fleet” is the primary tool for evading sanctions, using tactics such as changing vessels’ identities and registration records and transferring oil from Iran-linked ships to vessels that appear to have clean records. After passing through the Strait of Hormuz, vessels can conceal their tracking signals and take advantage of the vast expanse of open water, making their movements more difficult to detect. Miner added that monitoring such large areas requires a broad naval presence, giving vessels greater room to maneuver.
In many of the cases documented by satellite imagery, identifying information for vessels involved in the smuggling operations was concealed, surfacing only briefly. Those fleeting signals, however, were enough to identify the ships using the online vessel-tracking platform MarineTraffic.
Among the vessels MBN’s investigation identified as taking part in smuggling operations near the Iran-Iraq border in late May was the Destiny, an Iranian-flagged oil tanker under U.S. and European sanctions.
The Destiny can carry more than 280,000 metric tons of crude at maximum capacity. Records indicate that it is owned by the National Iranian Oil Company, while its movement patterns suggest it has been used as an initial transfer point in territorial waters.
The data also identified a smaller tanker, the Kush, carrying out similar smuggling operations. Navigational data provided by MarineTraffic showed that the Comoros-flagged Kush arrived at its position two days before the U.S. blockade began on April 12 and had not left since, giving it an unusual role in Iran’s oil-smuggling network.
Satellite imagery showed the Kush participating in several ship-to-ship transfers between April and August, indicating that it was being used as a floating storage facility.
The vessel has concealed its true owner since it was placed under U.S. sanctions in 2025, according to Equasis, a European Union-backed shipping database. Its last known owner was SAANVI Shipping, owned by a Panamanian businessman, Hector Varela de Leon, whom the United States sanctioned for his role in smuggling Russian and Iranian oil.
Data analyzed by MBN in the Persian Gulf and Gulf of Oman also identified about 135 instances in which the draft of Iranian oil tankers changed, something that occurs when a vessel’s load changes. In some cases, the draft changed more than once within a matter of days, consistent with the possibility that the vessels were being used to transfer cargo or serve as floating storage for smuggled oil.
The Kush’s repeated involvement in ship-to-ship transfers suggests it was one of those floating storage facilities.
Other vessels followed the same pattern, including the supertanker RHN, which can carry more than 2 million barrels of oil.
Satellite imagery documented the RHN taking part in an oil transfer with an unidentified vessel on May 1, during the U.S. naval blockade.
Navigational data available through MarineTraffic also showed that another vessel, the AMPAR 8, arrived at the same location where the RHN had been stationed several days earlier. It soon switched off its tracking equipment and disappeared from view.
MBN’s investigation tracked the AMPAR 8 after that date. Automatic Identification System, or AIS, data, which is used to track vessel movements, showed that it briefly headed to the port of Abu Dhabi before setting off toward the Indian port of Mumbai.
But a closer examination of the data showed that the vessel left the Emirati port without any change in its draft — the depth to which a ship’s hull sits in the water, which varies according to the weight of its cargo. The data also appeared to show the vessel covering long distances across Gulf waters in implausibly short periods.
Miner stated that could be linked to a practice known as “AIS spoofing,” in which a vessel’s reported position is falsified.
“It’s not a miracle of mechanical speed; it’s manipulation of the digital signal,” he said.
Some actors use devices that transmit false coordinates, he said, effectively removing a vessel from its real location and placing it somewhere else within seconds. The aim, he said, is to confuse monitoring systems and create false routes that obscure the cargo’s actual path.
The manipulation was not limited to ships disappearing and reappearing elsewhere. The data also showed dense, physically implausible clusters of vessels in confined stretches of water at various locations across the Persian Gulf, Gulf of Oman and Strait of Hormuz.
At first glance, those clusters can look like ordinary maritime congestion. But Miner said “this clustering is not random.”
When dozens of vessels are concentrated in a confined area, radar and thermal sensors become less capable of distinguishing individual targets accurately, he said. Such conditions, he added, create “an ideal environment for unauthorized oil transfers or for concealing the identity of high-risk vessels amid normal commercial traffic.”
According to Windward data, more than 1,650 vessels experienced interference with GPS and AIS signals across the Gulf region on March 7, 2026, while the company identified about 30 areas of signal disruption in the region.
Since the war began in late February, MarineTraffic data has recorded 284 instances in which Iranian oil tankers changed their names in the AIS information they transmit to maritime monitoring systems.
Company data analyzed by MBN also showed that 40 Iran-linked vessels, including two tankers, changed their flags during the war.
One identifier, however, is supposed to remain constant even when a vessel changes its identity: its International Maritime Organization, or IMO, number.
Miner said the ship-registration system makes it relatively easy to change a vessel’s flag and name. Its IMO number, however, is intended to remain the ship’s permanent identifier, akin to “a vehicle identification number.”
Iran’s shadow fleet, the U.S. expert said, has sought to circumvent even that safeguard by manually falsifying identification numbers on vessels and in electronic systems in an effort to conceal a ship’s identity entirely.
That makes verification increasingly difficult. A vessel’s name can change. Its flag can change. Its registered owner can change. Even the digital signal meant to tell the world where the vessel is can be manipulated.
And the effort does not end with altering a vessel’s identity. The next step is to change the identity of the cargo itself.
Miner told MBN that the more sophisticated tactic involves dilution and blending — mixing Iranian oil with crude from elsewhere to produce a blend whose origin is harder to distinguish through chemical analysis.
The concealment process thus forms an integrated chain: It begins with the vessel, moves to the cargo and then to commercial documentation, and ends with the financial network that receives the proceeds.
In the end, the oil does not disappear. Only its identity does.
Adapted and translated from the original Arabic.
