Shadow fleet uses dead ships' identities

Every ship at sea has a unique identity number, like a vehicle registration, that is supposed to be permanent and attached to that vessel for its entire working life. When a ship is scrapped, broken up for metal, its registration is supposed to be cancelled. What the shadow fleet is doing is taking the cancelled registration numbers of scrapped ships and using them on active, sanctioned tankers. It is the maritime equivalent of putting a dead person's driving licence on a car to evade police checks. Windward, a maritime intelligence company, tracked 14 of these ships carrying Iranian oil through the strait of Hormuz. The blockade makes this worse: because legitimate transit routes are now closed, there is more money to be made by cheating, so more ships will do it.