Strait of Hormuz Brief: 27 August, 2026

Executive summary

Rising tanker and gas carrier traffic pushed total Strait of Hormuz transits to their highest weekly level since the collapse of the memorandum of understanding, despite weaker bulker activity. Preliminary data show 108 transits during August 17-23, up 27% week on week. Volumes remain well below pre-crisis levels and beneath those recorded during the brief MoU period.

Positions hardened further this week. Washington launched its "Economic D-Day" sanctions escalation against Tehran, while Iran's Persian Gulf Strait Authority published a blacklist of 45 vessels, mainly tankers, accused of breaching unilateral transit rules. Despite expanding sanctions authorities and threatening an "economic onslaught", the US has yet to target major trading partners such as China or the UAE.

The bunkering sector is now directly exposed to sanctions risk. This week's designation of a UAE-based, Greek-owned bunker supplier materially alters the compliance landscape for fuel suppliers, operators and maritime service providers.

Key takeaways

Weekly transits reached a post-MoU high but remain well below normal levels. Preliminary estimates show inbound traffic rose 23% week on week and outbound traffic 32.4%. Crude exports continue to move through shuttle tanker and ship-to-ship transfer networks that concentrate risk on a relatively small group of vessels and crews repeatedly operating in high-threat waters. More tankers are entering the trade, particularly Gulf state-owned tonnage and vessels linked to South Korea's Sinokor.

Tanker and gas carrier movements rose by more than 50% during August 17-23 compared with the previous week, driven primarily by non-Iran-linked trade.

Source: Lloyd’s List Intelligence Strait of Hormuz Transit Monitor

Iran and Oman continue negotiations on an interim shipping arrangement that could create a temporary maritime corridor for limited commercial navigation through the strait. Washington has yet to respond substantively to the proposal, while Gulf state positions remain unclear.

The Trump administration has significantly expanded sanctions pressure, designating nearly 60 entities, vessels and individuals while broadening secondary sanctions authorities. The designation of a bunker supplier carries implications for a sector that had largely escaped direct enforcement action.

Iran has responded by increasing pressure on shipping, threatening penalties against vessels deemed non-compliant with its transit rules and publishing a blacklist targeting key Hormuz operators. The list includes 12 VLCCs responsible for more than 15% of crude liftings from the Middle East Gulf since the MoU collapsed in early July, underscoring the vulnerability of the shuttle tanker network sustaining regional exports.

Crewing is emerging as a critical operational constraint across conflict-affected trade routes. Operators are increasingly relying on wage premiums, specialist crews and enhanced welfare measures to maintain voyages through Hormuz and the Black Sea. At least 19 seafarers have been killed since the conflict began, according to the International Maritime Organization.

Security summary

A proposed Iran-Oman framework for Strait of Hormuz traffic would establish a temporary traffic separation scheme, routing inbound vessels through Iranian waters and outbound vessels through Omani waters while longer-term arrangements are negotiated. Iranian officials have stressed that the proposal is intended to manage commercial traffic rather than restore full freedom of navigation.

Iran's new blacklist identifies 45 vessels potentially subject to fines, detention or confiscation for alleged transit violations. The list includes ships linked to UAE, Greek and South Korean interests, several of which have previously been targeted by missile and drone attacks. Tehran has also warned that vessels conducting STS transfers or other business with blacklisted ships could themselves face sanctions.

The implications for the shuttle tanker trade are significant. Since the MoU collapsed, STS transfers in the Gulf of Oman have averaged 3.1m b/d, according to Vortexa, equivalent to almost 30% of the 5.6m b/d exported from the Middle East Gulf over the same period. If owners begin avoiding blacklisted vessels, the shrinking pool of shuttle tankers willing to transit Hormuz is likely to command higher freight premiums.

Iran continues to pressure vessels using the southern route. A Greek-linked tanker was struck by a projectile while transiting the Omani corridor this week, the third Greek-linked vessel hit this month. Freedom of navigation remains severely constrained, with owners, charterers and insurers continuing to treat Hormuz as a high-risk transit.

Specialist crewing models are becoming more common. Industry sources report that some vessels now deploy dedicated crews for high-risk Hormuz passages before changing personnel outside the conflict zone. Training and procedures continue to evolve, but operators acknowledge that commercial vessels remain effectively defenceless against missiles, drones and other military-grade threats.

Risk outlook

The proposed Iran-Oman transit framework represents diplomatic progress, but it focuses on managing risk rather than restoring normal operations. Questions remain over Washington's response to any arrangement involving joint Iranian and Omani oversight of the strait. Until commercial vessels can transit with confidence, elevated war-risk premiums and operational disruption are likely to persist.

The US "Economic D-Day" package materially increases compliance risk for owners, brokers, bunker suppliers and maritime service providers. The designation of a bunker supplier could prove a watershed moment for the bunkering sector, while additional measures promised by US officials may widen enforcement pressure across shipping services.

The logistics model that has emerged since July is markedly more tanker-intensive. Additional waiting time, repositioning voyages, STS transfers and longer trading patterns are absorbing capacity and tightening tanker markets. VLCC earnings have surged to record highs as vessel availability becomes constrained.

The same model concentrates risk on a limited number of ships and crews. Shuttle tankers operating between the Middle East Gulf and offshore transfer areas have kept oil flowing, but the network's dependence on a small fleet increasingly exposed to military threats and Iranian enforcement measures is becoming a key vulnerability.

The industry's resilience increasingly depends on people rather than ships. Rising wage premiums, specialist contracts and dedicated risk crews suggest that access to qualified seafarers willing to operate in conflict zones may become a major bottleneck. As owners face higher crewing, insurance, security and compliance costs, the price of moving energy and commodities is likely to rise. Prolonged exposure to conflict zones could also deepen the global seafarer shortage and further reduce operational flexibility.

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This briefing was compiled by the Maritime Intelligence Unit

All analysis focuses on cargo-carrying vessels over 10,000 dwt.