Iran’s tanker fleet is disappearing from the map as vessels turn off transponders ahead of oil sector sanctions on 4 November.

One by one, Iran’s tanker fleet is disappearing from the map. Tehran is making its oil exports as opaque as possible ahead of oil sector sanctions on 4 November.

Transparency has never been Iran’s forte, especially when it comes to the export of its economic lifeblood – oil. Clandestine exports of crude oil to Syria’s Baniyas refinery...