The one lane through Hormuz anyone certified clear is where Iran's mines keep going off

Two supertankers in a fortnight, both reported exploding on the southern route the Joint Maritime Information Center called clear in June - the route Iran calls unauthorised.

Published 2026-09-16 · analysis

Read the IRGC's mine reports for where they put the ship rather than for whether they embarrass Washington. Two of the three are placed south of the Strait of Hormuz - a supertanker on 31 August and the Algaya on Monday night - and on 31 August the IRGC gave the ship's offence outright: it was “attempting to pass through an unauthorised route.” That southern lane is the only stretch of this waterway anybody outside the war has ever certified as safe. On Iran's own account, the water that destroys ships is the water outside its corridor, and a hull is now at risk for its course rather than for its flag or its owner.

The certification is on this record and it is precise. On 19 June the Joint Maritime Information Center confirmed a mine near the recommended transit route, advised vessels to stay out of the main traffic-separation lanes, and confirmed the southern Omani-coast route clear, with Intertanko putting roughly 80 mines still to be cleared from the main channel. Eighty-nine days later that is still the only independent count anyone has published, and the map it drew has been turned inside out. The lane it cleared is where the explosions are being reported; where Iran's own corridor runs, nobody outside the war has looked since June.

This is a different instrument from the one that ran the closure for six months. Across the 120 incidents this site logs from 28 February to 14 August, 73 are attacks attributed to Iran - drones, missiles, boardings, rifles - and every one of them has an attacker attached to it. Not one is a ship striking a mine. Since 31 August there are three such reports in fifteen days, and the grammar has flipped: an attack names the attacker, a mine names the victim's navigation. Tehran says both things in the same morning. Five hours and thirty-six minutes after Mehr carried the burning supertanker, Tasnim carried a military source calling the American claim that Iran mines the strait “fantasy”. The third report, on 2 September, names the tankers' American control rather than their course; the two supertankers name the route.

The rest of the apparatus is being built in public, and on Monday it moved outward. On 6 September Mehr said three tankers on the southern route turned back after an IRGC warning; on the 9th the IRGC said it had targeted ten “violating vessels attempting to pass through the prohibited area”; the strait authority updated its blacklist on the 3rd. Monday added a rung that is not aimed at ships at all. The PGSA warned insurers, protection and indemnity clubs and classification societies against providing services to vessels on that list. Iran has required its own permits and war-risk cover since 19 June, but this is the first time in this record that it has gone after an owner's suppliers rather than the owner.

The regime is not emptying the strait. It is sorting it. Transits have been single-digit every single day for the 36 days since 8 August, but the week to 13 September carried 37 crossings against 22 in the week to 5 September - the most since the week to 14 August. Mehr's Monday report that transits had fallen to single digits over the weekend describes a threshold the strait crossed five weeks earlier, in what was on these numbers its busiest week in a month. None of it has a price attached: the last official close in this record is $109.51 on 9 September, before Monday entirely. So stop waiting for the next Iranian attack on a ship as the signal. The number that measures this blockade now is which lane the ships that are still moving decide to take.

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