Iran’s Persian Gulf Strait Authority has blacklisted 77 vessels for avoiding its toll regime in the Strait of Hormuz, yet none appear to have been deterred from continuing to trade in the region, according to analysis by Windward.
The authority, which opened in mid-May to oversee transits and toll payments through the strait, has released three tranches of blacklisted vessel names, on August 24, September 2, and September 14, Windward reports. Every one of the 77 vessels either used the “unauthorized” southern corridor through Omani waters or transited Iran’s northern corridor without paying tolls, the analysis found.
Tankers and Liberia-Flagged Ships Dominate
According to Windward, 85% of blacklisted ships were tankers, reflecting their heavy use of the U.S. military-assisted southern corridor to move oil exports from Gulf energy companies to market. Liberia-flagged vessels made up 38% of the list, or 30 ships, well ahead of Panama and Barbados at 6% each, which Windward links to Liberia’s popularity as a flag for companies such as ADNOC and Sinokor Marine that dominate southern corridor tanker transits.
Companies based in the UAE own or charter 40% of the blacklisted vessels, the largest share by country, followed by Greece at 12% and South Korea at 9%, per Windward’s findings. Sinokor Marine, which the report states shipped 40% of all crude moving via Hormuz in July, had at least eight tankers blacklisted, alongside vessels owned by Saudi state carrier Bahri.
Ships Keep Trading, Often Dark
Despite the blacklisting, Windward’s analysis indicates inclusion on the list has not stopped vessels from continuing operations in the region. Only 35% of blacklisted ships broadcast AIS location data in the two days leading up to September 16, though 61% transmitted AIS at some point during September, suggesting most continue trading with their tracking systems switched off. Just six of the 77 vessels transmitted AIS in waters west of Hormuz over the past seven days, according to the report.
Windward also notes that nearly all blacklisted vessels, except six, were assessed as holding P&I cover through the International Group of 12 P&I Clubs, which are prohibited from insuring ships that pay tolls to Iran. When adding more vessels to the list on September 14, the Persian Gulf Strait Authority reportedly referenced classification societies and marine insurers directly, stating they needed to protect against consequences arising from dealing with these vessels.
The report also flagged anomalies, including the bulk carrier BANASTAR, which had not transited Hormuz since the war began, and the Aframax tanker RIESCO, a U.S.-sanctioned vessel falsely flagged with Zimbabwe that was destroyed by CENTCOM on September 8.
Does This Matter to You?
The expanding blacklist and its apparent lack of enforcement power carry direct implications for tanker operators, charterers, and insurers active in the Gulf. With 85% of listed vessels being tankers and UAE-linked owners representing 40% of the list, companies moving crude through the southern corridor face growing exposure to Iranian designation despite continuing operations largely unaffected.
The insurance angle detailed by Windward is particularly relevant for marine insurers and P&I clubs, given that nearly all blacklisted vessels carry International Group cover, which is barred from insuring ships paying tolls to Iran. This creates a compliance tension for operators navigating both Iranian toll demands and Western insurance requirements. Vessel screening and AIS monitoring practices may also warrant closer attention, as most blacklisted ships have gone dark, according to the data.
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
