Saudi Red Sea oil exports go 'dark' as Houthi attack threat grows

Crude tankers loading at Saudi Arabia's Red Sea terminals are switching off their automatic identification systems before heading south, removing the market's clearest real-time view of a supply route that serves Europe. The vessels have been sailing dark to avoid giving Houthi drones and missiles a targeting fix, Reuters reported.

AIS transponders are mandatory under SOLAS, the International Maritime Organization's safety convention, for commercial vessels of 300 gross tonnage and upwards. They broadcast a ship's position, course, speed, and destination. The same signal powers the weekly export estimates published by services like Kpler and Vortexa and the loading counts commodity desks watch before official data lands. A dark tanker disappears from that record. Its position has to be inferred from satellite imagery, which passes over the strait only intermittently, so loadings at Yanbu and the smaller Red Sea berths carry wider uncertainty than the market is used to.

The Houthis have been attacking shipping in and around the strait since late 2023. Their strikes have sunk two merchant vessels and killed crew. A Greek-flagged crude carrier, the Sounion, burned for weeks after a 2024 strike before salvage teams towed it away. Going dark does not make a vessel invisible to radar; it removes the free position feed that guides a missile or an unmanned boat to its target.

Saudi Arabia has kept its Red Sea ports, Yanbu above all, running through the attacks. It has also maintained an uneasy truce with the Houthis while the United States and Britain strike Yemeni targets. Yanbu sits north of the Bab el-Mandeb. Every cargo leaving it for Europe still crosses the strait on the way to the Suez Canal. The kingdom is not at war with the Houthis; its tankers still sail the same water.