Both of the Gulf region’s critical shipping corridors are now effectively closed to normal commercial tanker traffic, according to maritime intelligence firm Windward. The company’s July 28 report describes the Strait of Hormuz and the Bab el-Mandeb strait as shut for different reasons, with tanker crossings collapsing on both fronts.
Hormuz: Zero Tanker Crossings
According to Windward, the Strait of Hormuz recorded just six total transits on July 27, split evenly between three inbound and three outbound movements. All six passed exclusively through the IRGC-controlled northern corridor, and none were tankers. Electro-optical imagery cited in the report showed a swarm of six IRGC high-speed craft holding position in the southern strait, alongside multiple dark, non-AIS-transmitting vessels moving through the waterway.
Windward attributes the closure to IRGC enforcement and the northern-corridor bottleneck, rather than a formal blockade declaration on this side of the Gulf.
Bab el-Mandeb: Insurance Withdrawal Drives Decline
On the Red Sea side, Windward reports that crossings through Bab el-Mandeb have fallen 22% since the Houthis declared a naval blockade on July 20, dropping from roughly 47.8 vessels per day beforehand to about 37.2 per day afterward. Tanker transits specifically fell 39%, while Saudi-linked crossings dropped 46%, the steepest decline among tracked vessel groups.
According to Windward, the sharpest fall in tanker movements followed a separate development: Lloyd’s market insurers began excluding Saudi-linked vessels from war risk cover starting July 24. Tanker transits fell to roughly 7.5 per day after that news broke, down from around 12 per day immediately following the blockade declaration. The report states this insurance withdrawal applies even to ships that merely called at a Saudi port in the past.
Crude Still Moving Through Workarounds
Despite both closures, Windward’s data indicates Iranian and Saudi crude exports continue under altered conditions. The firm assessed 102 potential “blockade-breaker” vessels near the Bab el-Mandeb line on July 27, including five Tier 1 candidates within roughly 65 nautical miles of the blockade, and two vessels believed to have already crossed undetected while operating dark.
On the Saudi side, Windward reports that the Yanbu King Fahd Industrial Port is now operating entirely AIS-dark, with 22 vessels detected across two July 28 imagery passes and 12 actively loading. The report also notes three China-linked VLCCs transited Bab el-Mandeb within two days despite the blockade, which Windward suggests indicates Chinese oil cargoes loaded from Yanbu have secured an exemption from Houthi targeting.
Windward additionally identified 158 vessels across five risk parameters as potentially exposed to Houthi targeting, including two Bahri VLCCs currently positioned inside Yemeni waters.
Does This Matter to You?
According to Windward’s assessment, the operational risk environment across the Strait of Hormuz, Gulf of Oman, northern Arabian Gulf, Red Sea, and Bab el-Mandeb is now rated Critical. The report describes both major corridors as effectively closed to normal tanker traffic, with active kinetic threats, structurally elevated dark-vessel activity, and evasion tactics spreading across the wider fleet.
For those tracking vessel routing, insurance exposure, or cargo movements through these corridors, Windward’s findings point to widening gaps between publicly visible AIS data and actual vessel activity, alongside shifting insurance conditions tied to Saudi-linked tonnage. The direct commercial impact will vary by trade lane and counterparty exposure, and further developments should be monitored through official advisories.
Gulf Bunkering does not provide operational or security guidance. This article is for informational purposes only. Operators should consult flag state authorities, P&I clubs, and relevant advisories for decisions relating to transit planning.
Sources: Windward
