31JUL

Hormuz crossings fall by two thirds

4 min read

09:24UTC

53 vessels crossed the Strait of Hormuz in the week to Monday, against 157 the week before. CNBC put the fall at 66 per cent, citing a named Lloyd's List Intelligence analyst.

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Key takeaway

Thirty tanker and gas-carrier crossings in a week, and a rising share of the rest sailing invisible.

53 vessels crossed the Strait of Hormuz in the week to Monday 20 July, against 157 the week before, a fall of 66 per cent. Tanker and gas-carrier crossings specifically dropped to 30 from 90. CNBC reported the figures on Tuesday, citing Bridget Diakun, senior risk and compliance analyst at Lloyd's List Intelligence ¹.

the strait is a 33-kilometre channel between Iran and Oman that carried roughly a fifth of the world's seaborne oil before the war. Diakun's count probably flatters what is left of the traffic, because a growing number of ships are sailing with their AIS (Automatic Identification System) transponders switched off. AIS is the beacon that continuously broadcasts a vessel's identity, course and position, and a ship that stops broadcasting stops appearing in the dataset the weekly count is built from.

Switching the beacon off buys a master a measure of protection from being aimed at, and costs him everything else. A dark ship forfeits the position reporting that underwriters price against and that naval escorts work from, so the traffic still crossing the strait is the traffic hardest to insure and hardest to shepherd. The silence also corrodes a signal that sanctions enforcement has leaned on for years. Going quiet used to be the signature of sanctioned Iranian and Russian cargoes, an evasion marker compliance desks screened for and reputable owners avoided at all costs: a sanctioned very large crude carrier loading at Kharg Island this month went to the trouble of faking an anchor swing rather than simply going dark, because going dark was itself incriminating . Once ordinary owners switch off for safety, the marker stops proving anything, and every screening model built on it degrades at the same moment.

Brent Crude reached $90.79 at 23:43 GMT on Monday, its highest since 11 June, and had eased back to $88.26 by Tuesday ² ³. Brent last appeared in this briefing on Friday 17 July, when war-risk premiums rather than any physical obstruction were doing the closing . A peak that retraces inside a day is the market pricing incident risk rather than scarcity, since no cargo has yet failed to arrive. The move still reaches a European forecourt about a fortnight later, which is where a shipping statistic stops being a shipping statistic.

Deep Analysis

In plain English

The Strait of Hormuz, the narrow waterway between Iran and Oman that roughly a fifth of the world's oil passes through, has seen shipping traffic collapse. Only 53 vessels crossed in the week to 20 July, down two-thirds from 157 the week before, according to data from Lloyd's List Intelligence, a shipping data firm. Fewer ships means less oil reaching buyers, which pushes the price up. Brent crude, the international oil benchmark, briefly topped $90 a barrel on Monday, its highest level in over a month, before easing back the next day. Insurance is a big part of why ships are staying away: with the route now dangerous, insurers charge shipowners far more to cover a vessel making the crossing, and many owners are deciding it is not worth the cost or the risk.

Deep Analysis

Root Causes

War-risk insurance pricing depends on continuous position data. When a ship goes dark, insurers lose the ability to distinguish a genuine transit from an evasive one, so cover gets priced at the ceiling for the whole dark-running population rather than case by case. That dynamic compounds the raw attack risk: even vessels that could plausibly cross safely now face the same premium as ones deliberately hiding sanctioned cargo, giving owners less reason to attempt the crossing openly at all.

The underlying attack pattern has not eased either: eight vessels crossed on 16 July against a pre-war range in the dozens, so the insurance mechanism is amplifying, not replacing, a genuine physical risk.

What could happen next?

Consequence
A 66% weekly fall in Hormuz transits is a larger and more sustained drop than any single-week figure reported earlier in the war, suggesting shipowners are now treating the corridor as effectively closed for planning purposes rather than merely elevated-risk.
Risk
If insurers cannot distinguish AIS-dark legitimate transits from evasive ones, war-risk premiums could remain elevated even after attacks ease, since the pricing signal (missing position data) would persist independent of the physical threat level.

Source Landscape

This story draws on mixed-leaning sources from United Arab Emirates and United States

United Arab Emirates

United States

Primary parallel: During the 1984-88 'Tanker War' phase of the Iran-Iraq War, sustained attacks on Gulf shipping pushed Kuwait to have 11 of its tankers reflagged and escorted under the US Navy's Operation Earnest Will from 1987, restoring the insurance and passage confidence that direct exposure had destroyed. The current collapse is the same underlying chokepoint mechanism: sustained attack risk making standard commercial cover unviable at any price shipowners will pay.

Counter-parallel: Earnest Will's reflagging worked because it added transparency: escorted convoys declared their status openly to secure protection and insurance. The current wave of AIS-dark running removes transparency instead, an opposite mechanism producing a similarly steep drop in recorded transits.

The immediate effect is a tighter physical oil market: fewer tanker crossings means less crude reaching refiners on schedule, which is the direct mechanism behind Monday's spike to $90.79 (highest since 11 June) before Tuesday's partial retrace to $88.26.

Structurally, the insurance market is doing as much to restrict supply as the attacks themselves. War-risk premiums running at 3-10% of hull value can exceed the profit margin on a single voyage, meaning some owners are withdrawing tonnage from the route entirely rather than sailing at a loss, independent of whether any individual crossing would in fact be safe.

Consensus view: War-risk insurers price transit risk using continuous AIS (Automatic Identification System) position data; a ship that goes dark forfeits the record underwriters rely on to verify its actual route and dwell time in the strait, which is part of why war-risk cover has already climbed to 3-10% of hull value from a pre-war 0.25% even before this week's near-total collapse in transits.

Counter-view: AIS-dark running was previously the signature of vessels moving sanctioned Iranian cargo rather than of ships avoiding danger ; mainstream tanker owners now switching off transponders for the same reason sanctioned operators do makes their motive far harder for insurers to distinguish from evasion.

Key tension: Whether insurers will end up pricing every AIS-dark transit as a war casualty regardless of motive, effectively forcing legitimate shipowners to choose between broadcasting a targetable position or losing cover altogether.

Sources:The National·Bloomberg·alanchand.com

Mentions:Strait of Hormuz →Brent Crude →CNBC →Lloyd's List →Iran →Automatic Identification System →Oman →Kharg Island →Kuwait →Iraq →Tanker War →Iran-Iraq War →US Navy →Operation Earnest Will →

First Reported In

Update #158 · Qatar bills Iran at the Security Council

The National· 21 Jul 2026

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Causes and effects

Caused by

Brent clears $87 as Hormuz traffic thins

The 20 July Brent peak and transit collapse extend the price and traffic trend recorded on 17 July.

Occurred 17 Jul 2026

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Three ships a day in an 'open' strait

Continues the collapse in Hormuz transits first measured at a 66% weekly fall on 21 July.

Occurred 24 Jul 2026

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This Event

Hormuz crossings fall by two thirds

The count understates the retreat, because a rising share of the ships still sailing have switched off the transponders that would put them in it.

Led to

Brent at $92 as premiums idle tankers

The 66% weekly fall in Hormuz transits recorded on 21 July is the baseline against which the 22 July Brent rise and CENTCOM's throughput claim are measured.

Occurred 22 Jul 2026

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Four mediators table a ten-day truce

Collapsing Hormuz transit volumes fed the mediators' push for a ten-day ceasefire.

Occurred 21 Jul 2026

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Different Perspectives

Shipping and insurance underwriters

Underwriters can price Houthi strikes because the group announces its targets, but an unclaimed drone at Damietta and a mandatory Iranian insurance scheme both deny them a pattern to price against. War-risk premiums are increasingly being set by the absence of a claimant, not the scale of the damage.

Jordan

Azraq absorbed its fourth Iranian strike in seven weeks, again drawing no direct Jordanian retaliation, only an American one. Amman's exposure, hosting US basing without the Patriot density of Gulf allies, has not changed even as the war around it widens.

Houthi movement

The Houthis' 20 July blockade of Saudi-linked shipping is the injury Riyadh's new 43-nation coalition directly answers, yet the group itself was never asked to join and remains outside every proposal on the table. Sanaa-aligned commentators call the coalition a paper reassurance for insurers rather than a deployable force.

Egypt's Cabinet

Egypt confirmed the Damietta blaze was an attack, not an accident, on soil the war had never touched before. Cairo now faces an unclaimed threat to a facility supplying roughly 7% of its domestic gas, with no author to hold accountable and no pattern yet to defend against.

Oman

Muscat is running the only channel Iran will use, a voluntary Hormuz fee modelled on Malacca, but stayed out of Saudi Arabia's new naval coalition entirely. Oman's mediating leverage depends on treating Hormuz as shared and non-exclusive, the opposite of what Tehran is now demanding of it.

Iraq's Prime Minister

Al-Zaidi cancelled his first official Riyadh visit and convened the Coordination Framework, the coalition that keeps him in power and whose factions sit inside the PMF that Saudi jets just struck. He is caught between a five-year Saudi investment relationship and armed groups inside his own state he does not fully control.