Crude exports through the Strait of Hormuz are continuing despite attacks on individual vessels, but traffic patterns are changing as tankers switch off AIS, sail in convoys and use ship-to-ship transfers to reduce exposure in the chokepoint.
Iran has demanded that vessels use the northern corridor through its territorial waters. However, rising volumes of Saudi, Iraqi and Kuwaiti crude, together with some UAE exports, are moving through the southern corridor, which remains supported by US air defence and naval assets.
Maritime intelligence analysis recorded 55 AIS-visible transits between 16 and 23 September, around 94% below pre-conflict levels of approximately 910 weekly movements. The figure is not considered a reliable measure of actual traffic because tankers are operating with their tracking systems switched off when safety or security risks are present.
The revised operating pattern relies on a tanker shuttle. Large crude carriers enter the Gulf with AIS disabled, discharge cargo through ship-to-ship transfers in the Gulf of Oman and return through the Strait. Cargo can then be divided between Suezmax tankers for onward delivery, reducing the number of vessels required to make the higher-risk passage.
Between 20 and 22 September, an estimated 26.72 million barrels of crude left the Gulf through the Strait. Around two-thirds was subsequently moved through ship-to-ship transfers. The three-day flow was equivalent to approximately 8.9 million barrels per day, although the figure reflects a convoy peak rather than a sustained export rate.
Saudi crude loadings at Gulf terminals have also recovered from August, reaching an estimated 3.9 million barrels per day during the first 27 days of September. Cargoes tracked from Saudi terminals were mainly bound for China and India, with some relayed through transfer points off Fujairah and Oman.
For logistics and energy-shipping operators in the UK and Europe, the developments add complexity to voyage monitoring, cargo visibility, insurance assessment and tanker availability. AIS gaps also make it harder to distinguish between stalled movements and vessels using deliberate tracking blackout procedures. Although exports have continued, the flows remain vulnerable to further attacks or escalation, which could quickly affect freight capacity, routing decisions and regional fuel supply risk.
