No consensus on how much oil Iran is still exporting as its tankers go dark

Daily exports could be as little as a couple of hundred thousand barrels, or exceed the 1 million a day shipped during previous sanctions under Trump's predecessor Barack Obama

While one Iranian tanker is attracting global attention, serious oil watchers remain absorbed by a bigger mystery: the hunt for the rest of Iran’s fleet.

The quest has led to ever more inventive methods of tracking ships, and divergent views on the amounts of crude secretly slipping into world markets. That’s because the vessels have mostly “gone dark” since sanctions were tightened this year, switching off transponders that would reveal their location. 

“Iran is a black box, but it’s also not a black box” as there are ways to uncover secretive activity, said Devin Geoghegan, global director of petroleum intelligence at Genscape