Most Iranian-flagged tankers have begun transmitting properly over the Automatic Identification System (AIS) without spoofing for the first time in seven and a half years, according to TankerTrackers.com.

The sudden shift, which began Tuesday, marks a significant change in the operational transparency of Iran’s maritime fleet. The reasons behind the decision remain unknown.

Two independent AIS data providers have confirmed the change in transmission patterns, TankerTrackers said.

For more than seven years, Iranian vessels have employed AIS spoofing techniques to obscure their actual positions and movements. The practice has been widely used to evade sanctions and monitoring of Iranian oil exports. The abrupt return to standard AIS broadcasting represents a notable departure.

Iran has previously vowed to retaliate against Western assets in the Middle East region if their vessels were provoked in any manner, according to TankerTrackers.

The timing and motivation for the switch remain unclear, and it is uncertain whether the change represents a policy decision by Iranian authorities or something else.