The Houthis Take Perim and Petroline Is Hit as Freight Rates Cross $1 Million a Day

At a Glance

• U.S. forces struck five IRGC-linked oil tankers on September 8, and three on September 5, as part of a new ‘tanker-for-tanker’ approach.
• Iran retaliated by striking the tanker NEW ANDROS in Iraqi coastal waters, ordering vessels away from Kuwaiti and Bahraini ports, and launching 20 ballistic missiles at a U.S. base in Jordan, of which 18 were intercepted.
• Houthi forces seized the Red Sea port of Mokha on September 10, the Hanish Islands, and by September 11 the island of Perim at the center of the Bab el-Mandeb, effectively taking control of Yemen’s Red Sea coastline.
• A pumping station for Saudi Arabia’s Petroline pipeline was attacked on September 10, with the pipeline preemptively shut down. Petroline carried roughly 92% of Saudi seaborne crude exports via Yanbu by June.
• VLCC spot rates to transit Hormuz and load inside the Middle East Gulf were assessed at just over $1 million per day this week, equivalent to approximately $26 per barrel, or 25% of the price of a barrel of crude at $100.
• AIS destination-field signaling near Bab el-Mandeb has broadened from Chinese-linked messaging to include Russian affiliation, Turkish armed-guard status, and crew religious composition.
• The bulker GLAMOR was hijacked approximately 38 nautical miles southwest of Balhaf, Yemen, on September 10.

Operational Overview

Saudi Arabia’s workaround to the partial closure of the Strait of Hormuz came under direct attack last week. Saudi Arabia diverted crude to the Red Sea port of Yanbu via the East-West pipeline. On September 10, a pumping station on the pipeline was attacked and preemptively shut down. On the same day, Houthi forces seized Mokha, followed by the Hanish Islands and, by September 11, Perim Island at the center of the Bab el-Mandeb, where the Strait narrows to approximately 20 kilometers.

VLCC spot rates to transit Hormuz and load inside the Middle East Gulf crossed $1 million per day, equivalent to approximately $26 per barrel against a normal freight share of 1 to 3%. U.S. forces struck five IRGC-linked tankers on September 8, with Iran responding by attacking a tanker in Iraqi waters with a drone.

Windward assesses the operational risk environment across the Strait of Hormuz, Red Sea, Gulf of Aden, northern Middle East Gulf, and Somali basin as critical.

U.S. Forces Strike Five Iranian Tankers, Iran Retaliates 

On September 5, U.S. Central Command struck three Iranian crude oil carriers after the IRGC launched ballistic missiles toward two U.S. Navy warships. M/T DOWNY (IMO 9218480) was permanently disabled off Kharg Island, M/T STARK 1 (IMO 9171450) near Jask, and the unladen M/T KYLO (IMO 9189146), also known as NOXEN, was completely destroyed in the Gulf of Oman and later sank after its crew was directed to abandon ship.

Three days later, on September 8, U.S. forces struck five more IRGC-linked oil tankers, bringing confirmed strikes across the two rounds to eight vessels. The vessels struck were M/T DERYA (IMO 9569700), M/T KAVIZ (IMO 9282041), M/T HORIZON 1 (IMO 9130456), M/T CHARMINAR (IMO 9318022), and M/T RIESCO (IMO 9251822).

HORIZON 1 is a Palau-flagged 115-meter LPG tanker carrying a high-risk designation. Vortexa data shows it laden with 37,400 barrels in floating storage. The vessel had been anchoring in the Strait of Hormuz East Waiting Area since August 30, transmitting AIS only intermittently. Imagery as of September 9 shows the vessel dark with no damage present, and smoke visible from the funnel.

DERYA is an Iran-flagged very large crude carrier. The vessel went dark off Sri Lanka in June 2026 and has not transmitted since. It has been sanctioned under OFAC secondary sanctions and the Iran SDN List since 2018.

KAVIZ is an aframax tanker falsely flagged with Comoros, sanctioned by the UK, the EU, and the U.S.  It went dark in the Gulf of Oman in April 2026. Vortexa data shows it was last reported carrying 736,900 barrels of Iranian heavy crude.

CHARMINAR is a falsely flagged Comoros MR product tanker, sanctioned on the U.S. Iran SDN list since 2025. Its last AIS location was on September 8 off the coast of Bandar-e Jask. Vortexa data shows it was last reported carrying 298,400 barrels of gasoil.

RIESCO is an aframax tanker falsely flagged with Zimbabwe, built in 2003, and sanctioned by OFAC on the Iran SDN list since 2025. Its last AIS position was in the Gulf of Oman as of September 8.

Iran retaliated across multiple fronts. The IRGC Navy warned tankers in the vicinity of Kuwaiti and Bahraini ports to leave the area. 

On September 9, Iran struck the Panama-flagged very large crude carrier, NEW ANDROS (IMO 9294252), in Iraqi coastal waters. Vortexa data indicates that the vessel was laden with 1.84 million barrels of oil and was being used for floating storage. 

On September 9, Iran launched 20 ballistic missiles at a U.S. base in Jordan. Eighteen were intercepted, and two landed in unpopulated areas with no reported casualties.

Iran attacked another ship on September 12. UKMTO reported that an unidentified vessel had been struck by an unknown projectile while transiting the Strait of Hormuz, with a fire reported onboard.

Separately, India’s Ministry of External Affairs reported that MT EL GAIA, a Panama-flagged tanker transiting with its AIS switched off and 25 crew aboard, including 14 Indian nationals, was attacked off the Omani coast. Omani authorities brought the fire under control and towed the vessel to port, with two crew members missing.

🚫 CLAIM: Iran's Islamic Revolutionary Guard Corps (IRGC) claims a Panama-flagged oil tanker recently struck a naval mine in the Strait of Hormuz. This is FALSE.

✅ FACT: The Panama-flagged oil tanker El Gaia was struck by an Iranian missile last month and rendered inoperable.… pic.twitter.com/JXi2X8d5oV

— U.S. Central Command (@CENTCOM) September 14, 2026

The Houthis Seize Mokha, the Hanish Islands, and Perim

On September 10, Houthi forces conducted a major offensive along Yemen’s southern Red Sea coast, seizing the city of Mokha and islands in the Hanish chain north of the Bab el-Mandeb Strait. By September 11, the group also seized the island of Perim at the center of the Bab el-Mandeb. The group likely has completely seized control of Yemen’s Red Sea coastline.

Windward MIOC assesses with high confidence that the Houthis will move quickly to consolidate control of Mokha and use its coastline to project further influence over the Strait and restrict supply lines to the anti-Houthi coalition.

What the Houthi Gains Mean for Maritime Control

The territorial expansion increases the group’s ability to project power over maritime commerce and access smuggling routes. Closer proximity to Bab el-Mandeb shipping allows the Houthis to use cheaper munitions against Saudi shipping, reserving longer-range and more advanced munitions for fighting the Republic of Yemen Government, striking Saudi Arabia itself, or threatening Israeli and U.S. assets. Mokha and the adjacent coastline also plug into the wider arms and drug-smuggling network, and Mokha’s loss as a Yemeni coast guard port reduces interdiction capacity while stretching UNVIM and Saudi forces across more coastline.

Houthi political figures have stated the objective is to pressure Saudi Arabia over its blockade of Yemen and that the group does not intend to seize the Bab el-Mandeb. With the capture of Perim Island, the group has effectively taken control of the Strait regardless. On September 10, the Houthi-controlled Humanitarian Operations Coordination Center indicated the Bab el-Mandeb remains open to all traffic except that linked to Saudi Arabia. Windward MIOC assesses with moderate confidence that the Houthis will not fully close the Strait to non-Saudi shipping in the near term, though targeting rules have previously been loosely implemented and inconsistent targeting could still result in strikes on non-Saudi vessels.

Yanbu and the East-West Pipeline Attack

Saudi Arabia has leaned hard on Yanbu since seaborne crude exports through the Strait of Hormuz plummeted in February and March. On September 10, multiple sources reported an attack on the pipeline, with the Saudi energy ministry confirming its preemptive shutdown to assess damages.

Saudi crude volumes shipped via the East-West pipeline from Yanbu totalled 3.2 million barrels per day in August, down from 3.8 million barrels per day in July, and up from 800,000 barrels per day in February, Vortexa data showed earlier this month. 

After the Houthis announced a blockade on Saudi ports on July 20, Saudi Arabia implemented further workarounds. VLCCs have shuttled crude to Ain Sukhna at the southern mouth of the Suez Canal to be carried via the SUMED pipeline to Sidi Kirir for loading and shipped around the Cape of Good Hope to Asia or markets in Europe. Loadings and exports from Yanbu are almost exclusively conducted with AIS off.

VLCC Freight Rates Cross $1 Million Per Day

Spot rates to charter very large crude carriers to transit via the Strait of Hormuz to load oil at terminals inside the Middle East Gulf were assessed at just over $1 million per day on Sept 11. These record-breaking and unprecedented rates have shocked the global oil, shipping, and chartering community and reflect the extreme risk and rising marine insurance costs to use the U.S. military-assisted southern corridor.

Rates reached approximately $500,000 daily last month and then climbed steadily since the U.S. military’s tanker-for-tanker pledge intensified tanker attacks.

Normally, freight costs are a very small percentage of oil logistics, comprising some 1 to 3% of the overall cost. At $1 million per day, this is equivalent to approximately $26 per barrel, or approximately 25% of the price of a barrel of crude at $100 per barrel. Such costs will further warp the global oil market, add to energy commodities costs, and spill over to other routes and tanker class sizes. Oman to China VLCC routes, which do not involve any Hormuz transits, are reportedly at approximately $600,000 daily, while West Africa to China rates are around $400,000 per day. An Aframax tanker shipping naphtha to Japan from the Middle East Gulf is at nearly $280,000 daily.

National Gulf energy companies are now reassessing their freight and logistics strategies. Many have their own fleet of tankers supplemented by spot tonnage as and when needed. But as the southern corridor has scaled, with approximately 6.5 million barrels per day of crude shipped over August, about 45% of pre-war levels, scarce available tonnage is pushing spot rates and asset prices to new records daily.

The market usually relies on single voyage charters, because energy majors typically do not own or charter ships for long periods when it is cheaper to charter tonnage on an as-needed basis. Now they are seeking the guarantee of always-available tonnage and are paying to buy and to ensure asset security. A five-year-old VLCC is now worth nearly $160 million versus a newbuilding valued at $130 million. That reflects the premium for immediately available ships as chokepoint vulnerability meets a need for asset security.

Saudi Cape Diversions Reach 14 Vessels

Since July 20, Windward AIS tracking shows 14 Saudi-flagged vessels rerouting around the Cape of Good Hope instead of transiting the Bab el-Mandeb Strait, amid continued Houthi attacks on Saudi-linked shipping in the Red Sea. The diversion adds an estimated 10 to 14 days and $0.9 to $1 million in cost per voyage, which across the 14 vessels amounts to roughly 140 to 195 extra vessel-days and $13 to $14 million in added voyage cost since July 20.

Bab el-Mandeb Traffic and Broadening AIS Identity Signaling

Since the seizure of Mokha on September 10, AIS-transmitting inbound traffic through the Bab el-Mandeb has not measurably changed, though outbound transits may already be declining, falling from 24 to nine between September 10 and 11. Three vessels were detected transiting dark on September 11, and additional vessels almost certainly transited undetected. As of 14:00 UTC on September 11, 16 tankers and 33 cargo vessels were transmitting AIS in the Strait across 19 flags, led by Panama and Liberia.

Following the Perim seizure, an uptick in AIS-transmitting vessels was observed, confirmed by satellite imagery from 08:01 UTC on September 14 showing no dark vessels transiting at that time. Seemingly counterintuitive, transmitting is a way to signal non-involvement in the conflict, which still exists for non-Saudi vessels.

Windward AIS data as of September 14 shows vessels broadcasting non-standard text in their AIS destination field instead of an actual port. Where this messaging previously centered almost exclusively on Chinese crew, ownership, or armed guards onboard, it has broadened to include Russian affiliation covering company, cargo, and armed guard, Turkish armed-guard status, and crew religious composition, alongside the standing Chinese-linked signaling.

These broadcasts advertising a particular identity or protection are done to reduce risk of attack. 

Since the blockade was announced,  the Houthis have allowed Saudi oil shipments destined for China and Pakistan to transit via Bab el-Mandeb, with no indication these arrangements will change. 

LNG Ship-to-Ship Transfers off UAE and Oman

Of the three transfers reported, two appear to involve LNG carriers damaged in Iranian attacks, with Qatar and the UAE transferring cargo to functioning ships. AL REKAYYAT (IMO 9397339), struck on July 7, transferred cargo to TEMBEK (IMO 9337731) according to reports, though AL REKAYYAT has been offline since the attack, so there is no AIS transmission to confirm. TEMBEK then sailed to India and discharged cargo on August 31.

GASLOG SHANGHAI (IMO 9600528), struck by Iranian forces on September 1, reportedly transferred cargo to GASLOG SAVANNAH (IMO 9352860) in early September, confirmed by AIS. Both have sailed from the region, with GASLOG SHANGHAI reporting via AIS that it is in ballast and GASLOG SAVANNAH reporting it is laden.

MRAWEH (IMO 9074638) reportedly transferred cargo to LNG ENUGU (IMO 9266994). The date could not be confirmed, as MRAWEH was dark from July 29, when it was last signalling west of Hormuz, until September 5, when it reappeared off India. LNG ENUGU sailed into the Omani port area twice over August, first around August 8 and then August 14, finally leaving the Gulf of Oman on August 23 signalling fully laden. After MRAWEH’s AIS transmission reappeared off India signalling fully laden, the vessel discharged a cargo on September 6. LNG ENUGU discharged its LNG cargo in Japan around September 4.

Pirates Board Greek-Managed Bulker Off Yemen

GLAMOR (IMO 9177961), a Saint Vincent and the Grenadines-flagged bulk carrier managed by a Greek organization, was boarded by a pirate action group approximately 38 nautical miles southwest of Balhaf, Yemen on September 10. UKMTO first received a report at 09:00 UTC of an unidentified skiff approaching the vessel around 98 nautical miles southwest of Al Mukalla, and MSCIO issued an alert at approximately 09:18 UTC that the vessel had been hijacked.

The crew stopped the vessel and shut down all systems before mustering in the citadel. Six armed pirates boarded but were unable to take control. EU NAVFOR Atalanta redirected assets to the area and, in coordination with the Combined Maritime Force, Japanese reconnaissance aircraft conducted show-of-force flights over the vessel. The pirates abandoned the ship. A subsequent search confirmed no unauthorised persons onboard, all crew were reported safe, and GLAMOR resumed its voyage toward Djibouti.

Atalanta describes this as the seventh piracy case since April 2026, with five vessels still held and 87 crew members captive. The incident coincides with the Houthi capture of Mokha, which would extend the group’s ability to threaten shipping or control the approach into the Red Sea.

SWARD (IMO 9174244), taken on April 26, was released on September 11 after 138 days in captivity. Puntland security sources told AFP a ransom was paid, though the amount has not been confirmed and reported figures vary widely. The St Kitts and Nevis-registered cargo ship was carrying fertiliser bound for Mombasa when boarded, with 17 crew comprising 15 Syrians and two Indians. Reports suggest pirates used the vessel as a mothership for further attacks, including the seizure of at least two Iranian dhows and the Cameroon-flagged LUTUF (IMO 9109134), which was itself released on August 17.

Vessels still held include HONOUR 25 (IMO 1099735), hijacked April 21, EUREKA (IMO 1022823), taken May 2, ASANA (IMO 9035838), taken July 17, and SIBU I (IMO 9204776), taken August 20 while bound for Port Sudan. MSCIO continues to warn vessels to maintain heightened vigilance within 150 nautical miles of the Somali coast between Mogadishu and Hafun.

An Unidentified Dark VLCC Trailing an Active Oil Slick Off Dubai

On September 10, EO imagery at approximately 0.5 meters per pixel, captured at 07:07 UTC, detected an unidentified 342m tanker operating dark approximately 45 kilometers off the coast of Dubai, laden and trailing an extensive, actively widening oil slick. No name, flag, or IMO could be established from the imagery.

The VLCC’s slick extends in a widening, feathered plume, a pattern consistent with an ongoing or recently active discharge. The vessel was not transmitting AIS at the time of image capture. The position sits within the high-traffic corridor serving Fujairah anchorage and Strait of Hormuz-bound routing. No corroborating AIS or Vortexa record is currently available given the dark status.

Written by Maya Romi, Windward Maritime Intelligence Content Specialist. Insights by Windward’s MIOC analysts.