Hormuz War-Risk Premiums Rise as Shipowners Grow Cautious Amid US-Iran Tensions

London marine insurers are recording a notable uptick in war-risk premiums for vessels transiting the Strait of Hormuz, while simultaneously seeing a reduction in the number of shipowners seeking cover for the strategically critical waterway, according to reporting by gCaptain. The dual signal — rising costs alongside falling demand — reflects a broader retreat by shipowners who are opting to avoid the strait altogether rather than absorb elevated insurance expenses, as tensions between the United States and Iran continue to intensify. The Strait of Hormuz remains one of the world's most consequential maritime chokepoints, with an estimated 20% of global oil trade passing through its narrow passage. Any sustained disruption to transit operations carries significant implications for global energy supply chains and freight markets. Marine underwriters in the London market, which serves as the global benchmark for specialist maritime risk, have historically been sensitive barometers of geopolitical stress in the region. The current hardening of war-risk rates echoes patterns seen during previous periods of US-Iran friction, including the 2019 tanker attacks in the Gulf of Oman that prompted a sharp spike in additional war-risk premiums. The pullback by shipowners signals a growing preference for risk avoidance over risk transfer — a posture that, if sustained, could begin to affect cargo flows and freight rates on routes dependent on Persian Gulf loadings. Tanker operators in particular face difficult commercial calculations, balancing the cost of longer alternative routings against the financial and physical risks of Hormuz exposure. For the broader shipping community, the development serves as a reminder of the market's vulnerability to geopolitical flashpoints. Operators with exposure to Middle East energy trades are advised to monitor underwriter guidance closely, review their war-risk endorsements, and engage with brokers regarding current Joint War Committee listed area designations. The situation remains fluid, and further escalation in US-Iran relations could prompt additional market hardening or, in more severe scenarios, the withdrawal of cover by some underwriters entirely.