Roughly 26.72 million barrels of crude exited the Strait of Hormuz between 20 and 22 September, even as attacks hit two tankers in the same three-day window, according to maritime intelligence from Windward and Vortexa reviewed by Waybill Wire.

The trades hid from view. Windward MIOC recorded 55 AIS-visible transits for the week of 16–23 September, roughly 94% below pre-war traffic near 910 a week. Vortexa's cargo data — independent of AIS — shows the barrels are moving just the same. Tankers are switching off Automatic Identification Systems under maritime-safety exemptions, running dark through the Strait and discharging via ship-to-ship (STS) transfer in the Gulf of Oman.

The corridor split

Iran has demanded that all Strait of Hormuz transits use the northern corridor through its territorial waters. But rising Saudi, Iraqi, and Kuwaiti crude, plus UAE barrels that cannot reach Fujairah by pipeline, are running the southern corridor. That lane still sits under USCENTCOM air defense and naval cover. Windward assesses that Iran is less able to constrain southern-corridor traffic than it was in mid-summer.

The 26.72 million barrels over those three convoy days equates to about 8.9 million bpd — a peak rate, not a sustained export pace. For context, Vortexa pegs Saudi Gulf loadings across 1–27 September at 105.6 million barrels, or 3.9 million bpd.

Saudi loadings quadruple

The Petroline attack on Saudi Arabia's East-West pipeline cut the kingdom's ability to move crude to the Red Sea, redirecting barrels back to Gulf terminals. Vortexa puts Saudi Gulf loadings for 1–27 September at 3,911 kbpd, more than four times August's 933 kbpd, though still 39% below January's pre-war 6,385 kbpd.

Visible AIS traffic tells a much bleaker story. Crude tanker calls at Saudi Gulf ports fell from 17 in July to 5 in August and 4 in September, with no VLCC calls visible in September at all. Vortexa's cargo data, which does not rely on AIS, shows crude tanker loads at Saudi Middle East Gulf ports climbing from 8 in June to 19 in August and 55 in September. Fifty of the September loads were VLCCs.

Bahri and Sinokor dominate the dark fleet

Of those September VLCC loads, Bahri — Saudi Arabia's national shipping company — operated 21. South Korea's Sinokor operated 14. Nearly all loaded with AIS off.

At Ras Tanura and Juaymah specifically, 35 crude tankers called with AIS on during 10–16 January. The same window in September saw just two tankers transmitting. Vortexa's cargo data shows loadings at those terminals fell from 52 to 16 a week — a real decline, but a smaller one than the AIS gap implies.

The last visible AIS surge came 1–10 July, as the Memorandum of Understanding window closed. Eight crude tankers departed Ras Tanura and Juaymah, declaring voyages to China, South Korea, Duqm and Fujairah. Seven were VLCCs, six of them Bahri-operated.

Where the crude is going

Vortexa tracks 33 September cargoes from Saudi Gulf terminals — roughly 58 million barrels — bound for China and India, more than three times August's 17 million barrels. Windward's Maritime AI platform identifies declared destinations for 13 of those cargoes: eight broadcasting China with ETAs between 4 and 15 October, and five broadcasting India. Most of the Indian-bound vessels had already reached Vadinar and Sikka by 28 September.

Some cargoes moved via STS transfer off Fujairah and Oman. The vessel loading the crude is not always the one delivering it, and the final destination can shift mid-voyage.

Strikes fail to slow exports

AL MARYAH (IMO 9393682) and LR STEPHANIE (IMO 9282625) took hits during the same 20–22 September window in which 26.72 million barrels cleared the Strait. Laden Gulf exits continued despite the damage. Windward MIOC assesses that, under current conditions, Iranian strikes are more likely to cause short-lived disruptions than a sustained drop in exports.

The crude recovery is real, yet exposed to further escalation. As East-West pipeline throughput returns and Saudi Arabia routes more barrels to Yanbu, Gulf loadings should ease — provided traffic through the Strait stays open.