65% of Outbound Tankers Switched Off AIS in Strait of Hormuz in May, Up From 37% Early in Conflict

About two-thirds of outbound oil tankers used shadow fleet tactics to pass through the Strait of Hormuz in May. Maritime analytics firm Vortexa reported that 65 percent of outbound tankers switched off their Automatic Identification System before and after transit, up from 37 percent in the first month of the conflict. Kpler data recorded 895 ships crossing the strait between March 1 and May 19.

The increase in AIS-off behavior indicates the practice has become an accepted operating protocol rather than an exceptional measure, Vortexa stated. Iran-linked vessels first established the template for switching off tracking systems. Non-sanctioned Gulf tonnage has since adopted similar methods and now accounts for the larger share of such transits in volume terms, according to the same analysis.

Iran offers safe passage through the strait for tolls of up to $2 million. Vessels linked with Iran, China, India, Pakistan and Japan have used the service, and Iran claimed dozens of ships were transiting under its supervision in recent days.

U.S. Blockade along the Gulf of Oman. U.S. Central Command intercepted 133 ships as of Thursday. Other vessels have taken routes closer to Oman’s coastline. U.S. Central Command said the Navy helped around 70 ships cross in the last three weeks.

Oil flows from the Middle East remain below pre-conflict levels. The average daily loss peaked at around 500,000 barrels in the first month of the conflict and rose to 710,000 barrels per day starting in May, Reuters reported.