Key facts
- Oil tankers in the Middle East are increasingly switching off their transponders for extended periods.
- This 'dark mode' activity has expanded from the Strait of Hormuz to the Bab el-Mandeb Strait.
- The duration of 'dark mode' movements has extended from hours to a week or more.
- This trend is driven by increased shipping risks in the region, including Houthi attacks.
- The extended 'dark mode' usage makes tracking oil flows from the Middle East more challenging.
A growing number of oil tankers in the Middle East are operating with their transponders switched off for extended periods, a practice known as 'dark mode,' as shipping risks in the region escalate. Initially concentrated in the Strait of Hormuz, this stealthy transit method has now extended to the Bab el-Mandeb Strait, where Iran-aligned Houthis have been targeting vessels. Ship-tracking data indicates that these 'dark mode' movements have lengthened from a few hours to a week or more. An example cited is the supertanker Romania Prosperity, which vanished from radar off Fujairah for 10 days in late July. This increased use of 'dark mode' significantly complicates the transparency of oil flows out of the Middle East, making it difficult for market observers to estimate actual export volumes.