The war's second strait is at zero, and it died at Hormuz's speed

Russia closed the Kerch Strait on 10 July; thirteen days later its 7-day average fell below one transit. Hormuz took fifteen.

Published 2026-08-24 · analysis

A second strait went to functional zero this summer, and it was sitting in the same file this site reads every week. The Kerch Strait — the only sea passage between the Sea of Azov and the Black Sea — carried 12.1 transits a day through the first half of 2026. In the first sixteen days of August it carried four. Not four a day: four transits in total, with seventeen of the last twenty-seven days at zero. Hormuz's collapse has a companion, and it went unwatched among the twenty-eight chokepoints PortWatch counts.

The mechanism is the mirror image of Hormuz. After Ukrainian drone strikes on tankers and cargo vessels in the Sea of Azov, Russia's border service closed the strait on the evening of 10 July — passage requests would no longer be accepted, with no reopening date given. Iran closed Hormuz against its adversaries' shipping; Russia closed Kerch to shelter its own. A blockade imposed in one sea, a lockdown ordered in the other, and the transit file records the same thing for both: ships stop.

The order did not stop the traffic — the decay did. In the ten days up to and including the order, 54 vessels transited. In the ten days after it, 21 more did, six of them on 12 July alone, two days after passage requests stopped being accepted. The seven-day average did not drop below one transit a day until 23 July, thirteen days after the strait was declared shut. A strait does not close on the evening it is closed.

Hormuz took fifteen days to cross the same line: declared closed on 28 February, its seven-day average first fell below one a day on 14 March. Two wars, opposite mechanisms, and nearly the same die-curve — roughly two weeks from order to functional zero. The tails, though, have diverged. Hormuz climbed back to a trickle and holds it: 3.8 transits a day across the first sixteen days of August, and seventeen zero-transit days in five and a half months of closure. Kerch logged seventeen zero days in its first twenty-seven.

What this file cannot say is where the Azov's cargo went. Russian grain can move by rail to Black Sea ports that are not chokepoints, so the substitution arithmetic that worked for Bab el-Mandeb and Hormuz has no denominator here, and observed transits are a lower bound everywhere — a ship with its transponder off is not counted. What the counts do say is narrower and stranger: of the twenty-eight chokepoints PortWatch measures, two are now at functional zero, they got there in the same summer, and they got there at the same speed. The thing to watch is the tail — whether Kerch finds a Hormuz-like trickle, escorted or insured or dark, or stays at the zero the last four weeks show.

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