Skip to content
Welcome, thoughtbot's Giant Robots listeners!Start here
Autonomous Systems: Land & Sea
13JUN

500 ships idle as Hormuz stays shut

3 min read
11:07UTC

Zero new tankers crossed Hormuz in the 24 hours after Trump's signature; more than 500 ships stayed anchored as Bimco called a crossing very risky.

TechnologyDeveloping
Key takeaway

Brent priced an open strait that no tanker actually crossed; insurers still block transit.

Zero Hormuz tankers transited in the 24 hours after Trump's 16 June signature, despite his declaration that the strait was open. The two crossings logged on 15-16 June were toll passages under the Islamic Revolutionary Guard Corps (IRGC) authority, Iran's military force that controls mine routes and passage conditions, not a reopening. More than 500 ships remain parked in the Gulf⁠1. Bimco, the world's largest shipowner association, calls a crossing "very risky": the floating mines are still live, no IRGC order has cleared the lanes, and not one Protection and Indemnity (P&I) club, the London-based mutual marine insurers, has lifted its Hormuz war-risk exclusion⁠2.

The insurance point drives the lanes more than the mines do. A tanker without P&I cover cannot dock, because terminals and lenders refuse an uninsured hull. The blockade now runs through London insurance underwriters as much as through Iranian mines, and every owner knows it. Jakob Larsen, Bimco's chief safety officer, said owners "still consider it very risky to commence transits at this point" while the mines stand uncleared.

Brent Crude, the global benchmark that prices roughly two-thirds of internationally traded oil, fell to between $78.82 and $81.55 on the signing, down as much as 5 per cent⁠3, near the two-month low it touched a week ago on deal optimism. Markets priced the expectation of an open strait. No moving ship lay behind the fall, because the lanes held zero new transits. The price moved; the cargo did not.

Deep Analysis

In plain English

When a ship sails through a war zone, it needs special war-risk insurance. The P&I clubs, mutual insurance associations based in London, provide this cover for roughly 90 per cent of the world's ships. They said on 16 June that the Hormuz strait is still too dangerous to cover, because Iranian military mines remain in the water and nobody has officially certified them as swept. Without that cover, a shipowner who loses a vessel in the strait cannot claim for the loss. No credible insurer will touch an active mine zone. This is why 500 ships are sitting in the Gulf, not because their owners do not want to move, but because sailing uninsured through an uncleared mine field is commercially and legally impossible.

Deep Analysis
Root Causes

The 500-ship backlog and zero-transit outcome have two distinct root causes. The mine threat is physical: CENTCOM's own assessment by mid-May was that 90 per cent of Iran's naval mine stockpile was warehoused, not in-water, but the remaining deployed mines have not been certified as swept. Bimco's Jakob Larsen cited active mines as the primary safety barrier.

The P&I club constraint operates through the International Group of P&I Clubs, which covers roughly 90 per cent of the world's ocean-going tonnage. The group sets a collective de-risk bar that no individual member club can unilaterally lower without triggering reinsurance withdrawal by the London market. P&I clubs cannot issue standard hull and liability cover for a zone the Lloyd's Joint War Committee lists as enhanced-risk without a UN resolution or government certification of safety.

What could happen next?
  • Consequence

    P&I de-listing of Hormuz requires mine clearance certification or a UN resolution; the 60-day nuclear talks window does not address either condition.

  • Risk

    Oil markets pricing a reopening that has no ships behind it face a correction risk if Friday's ceremony also fails to produce mine clearance progress.

First Reported In

Update #130 · Trump signed the war over; it kept going

Argus Media· 17 Jun 2026
Read original →
Different Perspectives
DNV and Fassmer
DNV and Fassmer
Signed a memorandum at SMM in Hamburg, announced on 10 September, to seek an approval in principle for autonomous naval vessels. DNV's Rasmus Stute said autonomy is "becoming one of the key pillars in defence".
Belgian Ministry of Defence
Belgian Ministry of Defence
Awarded Exail Robotics Belgium €9.87m on 14 September, without competition, for three TRIDENT systems carrying the K-STER C mine-disposal vehicle for Ukraine. It had tendered separately in July for twelve tethered ROVs, not yet bought.
IRGC Navy (Iran)
IRGC Navy (Iran)
IRGC spokesman Hossein Mohebbi said the IRGC Navy seized a US Kingfish mine-hunting vehicle in the Strait of Hormuz on 27 September, valuing it at several million dollars. US Central Command calls the claim "clearly desperate"; no verified imagery exists.
UK Defence Intelligence and Kraken
UK Defence Intelligence and Kraken
Defence Intelligence said the 12 September clash "almost certainly marks the first time" Russian and Ukrainian USVs engaged directly. Kraken meanwhile trialled an unarmed Saab radar picket boat on 5 and 6 October.
Ukrainian forces and ARX Robotics
Ukrainian forces and ARX Robotics
A Ukrainian Sargan-3000 destroyed a Russian robot boat on 12 September, and the first ARX GEREON ground robots reached Ukraine on 29 September. The Sargan-3000 carries a mounted gun.
Indian Register of Shipping
Indian Register of Shipping
Certified Accurate Industrial Controls' ISACA collision-avoidance software to IMO standards after five audited milestones and 2,500 hours of trials. The firm plans to use it converting six Indian Navy patrol boats.

Written with AI from Lowdown's published reporting. Not individually reviewed by an editor. Editorial standards.