Oil Tankers Disable Transponders to Evade Iran and Houthis

Oil tankers are increasingly disabling their transponders for extended periods to transport crude through the Strait of Hormuz and the Bab el-Mandeb strait. While vessels previously went dark for only a few hours, some clandestine journeys now last a week or more to avoid detection and potential attacks by Iran.

Between July 14 and early August, approximately 62% of oil and product tankers crossed the Strait of Hormuz without broadcasting their locations. This represents an increase from roughly 50% prior to the United States reinstating its maritime blockade of Iran on July 14. The trend has been further accelerated by the Houthi militant group's announcement of a blockade on Saudi Arabian oil in the Red Sea in mid-July.

Shipowners continue to utilize these dangerous chokepoints due to high profitability. To further mask cargo movements, some vessels engage in shuttle trade by transferring oil to other ships just outside the Strait of Hormuz.