UKMTO says threat to Hormuz shipping 'severe', further attacks 'highly likely'

Eight attacks involving projectiles of unknown origin were reported against vessels in the Strait of Hormuz on 11 and 13 October. The incidents involved four tankers and four container ships. One vessel, the GFS Pride, caught fire and sank on 14 October.

The attacks were part of wider harassment activity attributed in the advisory to the IRGC. This included UAV overflights, targeted surveillance of merchant shipping, and occasional hailing on VHF radio. These actions can pressure crews, disrupt voyages, and make ships uncertain about where they can safely travel.

UKMTO said the activity showed Iran’s intent to assert a presence along key transit lanes and maintain pressure on passing vessels. It warned that the threat remained severe and further attacks were highly likely under current conditions. Ships also faced an elevated risk if their identification systems were switched on.

The Strait of Hormuz is a narrow sea passage between the Persian Gulf and the Gulf of Oman. It connects the Gulf’s ports with the Arabian Sea and global shipping routes. Merchant vessels use it to enter or leave the Gulf, including tankers carrying energy supplies and container ships carrying trade goods.

Its geography concentrates shipping into a limited corridor. That makes the route efficient, but it also creates vulnerability. A threat, attack, or order to divert can affect many voyages at once. The article reports that traffic in both directions had fallen to single-digit levels according to independent tracking data.

The waterway therefore matters far beyond one local route. UKMTO described the threat to merchant shipping as severe and said further attacks were highly likely under current conditions. Reduced traffic can delay cargoes, increase insurance and security costs, and force companies to consider longer or less efficient alternatives.

The advisory reported 149 maritime security incidents across the region since 1 March. That figure shows the crisis is not limited to one isolated encounter. It reflects a sustained security problem affecting commercial vessels and the routes they depend on.

Traffic measurements varied by source. Independent tracking data indicated single-digit vessel traffic in both directions through the Strait of Hormuz. Separately, US NCAGS data showed assisted traffic flows averaging approximately 30 vessel transits per day during the previous 96 hours.

These figures are not necessarily contradictory because they use different tracking or assistance measures. Together, they show that some shipping continues, but movement is constrained and closely monitored. The low independent counts suggest many operators may be delaying, rerouting, or avoiding the waterway while the threat remains severe and further attacks are considered highly likely.

The Strait of Hormuz is a concentrated shipping route, so widespread avoidance could slow the movement of oil and other cargoes. Tankers might wait offshore, take longer routes, or reduce sailings. Those choices would increase travel time, fuel use, insurance costs, and security expenses.

For example, a tanker delayed or diverted from the strait would deliver its cargo later. If many vessels faced similar delays, buyers could compete for fewer prompt supplies. Energy markets often respond to expected shortages as well as actual ones, so prices could rise even before supplies were fully interrupted. These market effects are established consequences of major shipping disruptions, not figures given in the article.

The article does not quantify any effect on fuel supplies or prices. It does show that traffic was already low by independent tracking, while the threat remained severe. If attacks continued and more ships stopped using the route, delays and price pressure would likely become more pronounced.

UKMTO, the UK Maritime Trade Operations centre, provides security information and warnings for merchant shipping. In this case, it issued the latest advisory on behalf of the Joint Maritime Information Center, or JMIC. Their role is to collect, assess, and communicate information so ships can judge risks.

The advisory attributed continuing attacks, attempted attacks, and harassment activity to the IRGC. IRGC stands for Iran’s Islamic Revolutionary Guard Corps, an Iranian military and security organisation. The reported activity included UAV overflights, targeted surveillance, and occasional VHF hailing of merchant vessels.

These organisations have different functions in the crisis. UKMTO and JMIC inform the maritime community, while the IRGC is identified as the actor conducting or attempting the hostile activity. The warning that the threat remains severe helps operators decide whether to continue, delay, reroute, or strengthen precautions.

If the Strait of Hormuz became too dangerous, oil tankers could take longer sea routes around the Arabian Peninsula, where ports and navigable waters permit. Cargo ships could similarly reroute through other regional ports and ocean corridors. These alternatives would add distance and time rather than provide a simple replacement.

Oil producers may also use pipelines that bypass the strait, where such pipelines exist and have spare capacity. Some cargo could move by rail or road after unloading at alternative ports, while air freight could handle a small share of urgent, high-value goods. These alternatives are established transport options, but the article does not identify specific routes or capacities.

The practical result would depend on cargo type, port capacity, pipeline availability, and security conditions. Longer routes would consume more fuel and raise costs. If many vessels avoided the strait simultaneously, alternative systems could become congested, limiting how quickly they could replace normal maritime traffic.

AIS, or the Automatic Identification System, is a maritime safety system that broadcasts a vessel’s identity, position, course, and speed. Ships use it to help authorities and nearby vessels understand traffic patterns, reduce collision risks, and coordinate responses. It also supports monitoring in busy waterways.

During a conflict, however, a live transmission can reveal where a merchant ship is, what it is doing, and which route it is following. An adversary could use that information for surveillance, targeting, or directing the vessel toward a controlled route. Turning AIS off can reduce visibility, but it may also create safety and compliance concerns.

The advisory specifically warned that vessels travelling with their identification systems switched on faced an elevated risk of being targeted or ordered to divert toward Iranian-controlled routes. That warning creates a difficult balance between normal maritime transparency and operational security during a crisis.