Prolonged restrictions on shipping through the Strait of Hormuz are approaching an important milestone for the marine insurance market. From next week, affected vessels will begin reaching the first six-month (183-day) Blocking & Trapping threshold, bringing potential exposure increasingly into focus.
Blocking & Trapping clauses may respond where an insured vessel is prevented from leaving an area for a specified period following an insured event, without necessarily suffering physical damage. Policy wordings vary, with six, nine and twelve month duration periods, although 12 months is understood to be the most common.

Commercial shipping experienced a significant increase in hostile activity during the past ten days across two key maritime regions. In the Persian Gulf, a series of attacks damaged several high-value commercial vessels transiting the Strait of Hormuz. In the Sea of Azov, Ukraine intensified its drone campaign against Russian-linked shipping, targeting vessels supporting oil exports and logistics to occupied Crimea.
While the nature of the campaigns differs, both highlight the rapidly changing war-risk environment facing the marine insurance market.

A “safe passage” framework built on an interim US–Iran agreement lasted less than a season. On July 7, four vessels were struck, damaged, or coerced within hours of one another near the Strait of Hormuz – the clearest signal yet that the ceasefire is not translating into insurable stability, and that the market’s aggregation assumptions for the Gulf need re-testing now, not at renewal.

The security environment in the Persian Gulf has undergone a fundamental structural shift following the escalation that began on February 28, 2026. For the (re)insurance market, the Strait of Hormuz has transitioned from a high-risk transit corridor to an active conflict zone, resulting in a near-total suspension of commercial traffic and a critical concentration of hull and cargo exposure.

The escalation of hostilities in the Persian Gulf since 28 February 2026 has fundamentally altered global maritime risk patterns. With the Strait of Hormuz effectively closed to commercial shipping, insurers are now confronting one of the largest geographic redistributions of energy transport risk in modern shipping.