TankerTrackers.com on Sunday cited satellite images that it said showed Iran loaded at least 4.6 million barrels of crude at export terminals in recent days, with another four million barrels appearing to have crossed the US blockade line.
The figures suggest Tehran retains at least some ability to keep oil flowing despite a US naval blockade launched nearly two weeks ago and repeated claims from Washington that the operation is crippling Iran’s maritime trade.
How effective has the blockade been?
US Central Command has portrayed the blockade as increasingly effective.
In its latest update on April 25, CENTCOM said US forces had “redirected” 37 vessels since the blockade began against ships entering or departing Iranian ports on April 13.
US forces have also expanded enforcement beyond the Persian Gulf, intercepting or seizing tankers in the Indian Ocean and Arabian Sea suspected of carrying Iranian crude.
Washington has framed the operation less as a hermetic seal than an economic squeeze. US officials argue the blockade’s effectiveness should be measured by whether Iran’s revenues are being cut.
Independent maritime trackers, however, paint a more complicated picture.
How is Iran still moving oil?
Shipping intelligence firm Lloyd’s List Intelligence reported this week that at least 26 vessels linked to Iran, including 11 oil and gas tankers and two very large crude carriers, have sailed in and out of Iranian ports since the blockade began.
The Financial Times, citing cargo tracking firm Vortexa, reported the figure could be as high as 34 Iran-linked tankers bypassing the blockade line in the Strait of Hormuz, including six outbound tankers carrying around 10.7 million barrels of crude.
Vortexa has also identified multiple fully laden tankers slipping past US warships. Bloomberg reported that a wider flotilla may have moved roughly nine million barrels around the blockade in recent days.
Iran’s so-called shadow fleet has long relied on tactics such as switching off AIS transponders, spoofing vessel locations, conducting ship-to-ship transfers, relabeling cargoes and using front companies to disguise ownership and destinations.
Since the blockade began, shipping analysts have observed vessels “going dark” near Iranian terminals before reappearing beyond the enforcement line.
Others have hugged coastal routes or moved through narrow shipping lanes where interception becomes more politically and operationally difficult.
What impact is the blockade having?
Even so, the blockade appears to be having an impact.
Traffic through the Strait of Hormuz has dropped sharply from normal levels, insurers have raised premiums, and some buyers have reportedly delayed or canceled purchases amid legal and logistical uncertainty.
Higher freight rates and longer voyages are also increasing costs for Iranian exports and for customers, chiefly in China.
The longer the blockade persists, the greater the chance Iran faces storage bottlenecks at export terminals or is forced to shut in production.
For now, the blockade appears to be functioning less as an impenetrable wall than as a bottleneck: slowing, complicating and raising the cost of Iran’s oil trade without stopping it entirely.
That may be enough for Washington to claim success and enough for Tehran to claim survival.
