Independent shipping data show traffic through the Strait of Hormuz at its lowest level since May, a picture that sits awkwardly beside the US Navy's own account of stepped-up tanker escorts. The strait is one of the world's most critical energy chokepoints, with roughly a fifth of globally traded oil and a significant share of liquefied natural gas passing through it, meaning even short-lived disruptions carry outsized significance for seaborne energy supply.

Kpler's 10-day moving average showed just 10 commodity vessels transiting the strait per day, the lowest since May, according to Reuters. That is down from more than 15 on Friday and nearly 13 on Saturday, with only two vessels passing through on Saturday and six on Sunday — most of them using the Iranian route.

The decline follows a sharp escalation over the weekend. US forces struck three Iranian oil tankers on Saturday, including one off Kharg Island, Iran's key export hub, after Iran's Islamic Revolutionary Guard Corps (IRGC) attacked US warships in the region. In retaliation, the IRGC navy said it targeted three tankers travelling unauthorised routes in the strait, along with three additional US vessels in other areas. The three Iranian tankers — named Downy, Stark I and Kylo, also known as Noxen — were identified by maritime intelligence firm Marisks.

Marisks described the Saturday attacks as a major escalation in the maritime conflict, warning that commercial tankers are now being used as instruments of reciprocal economic pressure, eroding the previous distinction between military confrontation and commercial shipping. The firm assessed risk as extreme for Iranian or Iran-linked tonnage, and materially elevated for US-linked or US-escorted shipping throughout the Strait of Hormuz and the Gulf of Oman — a risk framing that sits uneasily alongside the Navy's own characterisation of its escort activity.

The disruption extends beyond crude. A tanker carrying refined products loaded from a Saudi port attempted to exit the strait but was turned back, according to LSEG data, while no very large crude carrier (VLCC) has exited since Wednesday, Kpler data showed. On Sunday, one VLCC and three bulk carriers laden with metals, grains or oilseeds entered the strait. The UK Maritime Trade Operations office (UKMTO) noted in its weekly report that 27 projectile strike incidents since 6 July have caused damage to vessels operating in and around Hormuz. Bulk carriers carrying metals, grains and oilseeds are not normally the focus of Gulf security tensions, and their presence among the transits underscores how broadly commercial shipping through the chokepoint is now exposed.

The gap between the Navy's account and the independent traffic data is itself a market-relevant signal. Kpler's 10-day average of just 10 vessels a day points to genuine physical tightness in Hormuz-transiting supply regardless of how safe passage is being characterised publicly, keeping the geopolitical risk premium in oil firmly intact. With Marisks assessing risk as extreme for Iranian-linked tonnage and materially elevated for US-linked shipping, insurance and freight costs for any vessel attempting the route are likely to stay elevated, reinforcing upward pressure on landed crude costs even before accounting for the direct loss of throughput. The fact that a refined products tanker was turned back while attempting to exit adds a further squeeze on product availability layered on top of the crude disruption.

Whether the Navy's escort claims and the observed traffic figures can be reconciled remains unclear from the available data, and the two accounts should be treated as separate, unverified claims pending further confirmation.