Kerch now moves in a month what it once moved in a day

In the 30 days since Russia’s suspension of Kerch Strait transit applications took effect, 34 vessels have passed — fewer than the strait’s 2019–23 baseline moved in an average day. Fourteen of those thirty days recorded no transit at all, including the last four in the data. The 30-day average now reads 1.1 against a baseline of 37.4, which is −97.0%, and −91.6% against the strait’s own already-collapsed trailing year. The Stress Index reads 39.3, Settled.

Two ships in nine days

Two weeks ago this site reported that Kerch had fallen to 3.1 transits a day over 1–26 July, after Russia’s border guards stopped accepting applications for passage from the evening of 10 July. The remaining five days of the month pulled July down to 2.8, from 11.2 in June, on IMF PortWatch satellite AIS counts current to 9 August.

August is barely a series. Two vessels in nine days — one on the 1st, one on the 5th — and none on the other seven, with the final four days of data, 6 to 9 August, all blank. The zeros are not a reporting gap: they sit inside a month of near-zeros, fourteen blank days spread across the thirty since the suspension. An AIS count reads only transponders that are on, a live caveat on a route whose traffic was being described as shadow-fleet tankers even before the strikes — so these figures are a floor. But a floor of zero, held for days at a stretch, is the finding.

The marker the last piece set has moved the wrong way

That earlier piece closed by watching for daily transits to clear 20 again, the October 2025 level, as the line separating a suspension from a closure. The highest single day since the notice is six, on 12 July.

The other line is closer. The lowest the 30-day average has ever been is 0.2 a day, set on 14 November 2024. The latest 1.1, for the 30 days to 9 August, is the lowest reading since 22 November 2024 — and if no vessel moves, the arithmetic of the rolling window alone drags the average below the 2024 record on 26 August. The gap between “worst since 2024” and “worst ever” is seventeen more blank days.

The third stop in three years, and the first at the top of the season

Kerch stopping is not new; that is the honest context. The route recorded 142 zero days in 2024, bottomed near a third of a vessel a day that September, collapsed again into February 2025, and recovered each time — reaching 20.7 a day in October 2025. A count that has round-tripped twice cannot be assumed closed for good on five weeks of data.

What is different is the calendar. August is this strait’s high season: across 2019–2021 the month averaged 61 to 69 transits a day, the busiest 30-day stretch in the whole series peaked on 2 August 2019 at 72.5, and the single busiest day ever recorded is 11 August 2020, at 106 vessels. The two dead Augusts of 2023 and 2024 came deep inside a long decay. This one arrived in six weeks, from a June that still ran 11 a day. The strait has now spent 1,717 consecutive days more than 15% below its baseline on the 30-day measure — a streak that began on 27 November 2021, before the invasion, and that this month has stopped being about degree.

The other end of the Black Sea is still setting records

When the July piece ran, the Bosporus was at 74.5 transits a day, the lowest in its series. It has since shed another seven: 67.4 on 9 August, a record low set on the latest day of data, 30.6% below its 2019–23 baseline and 22.5% below its own trailing-year average. Kerch is a war story; the Bosporus is every Black Sea economy’s story, and both ends of the basin are narrowing in the same month.

The index will not see any of this for a while. The Stress Index reads 39.3, Settled, and its trade-activity input — a global freight-derived series — is observed 73 days behind. Whatever the Black Sea does in August reaches that gauge around November.

What a transit count cannot settle

It cannot distinguish a closed door from an empty road — whether ships are being refused passage or owners have stopped asking. It cannot see vessels waiting at anchor, and it cannot see vessels running dark. When and how much are in the data; why never is.

What to watch

Tuesday’s PortWatch batch. The data ends 9 August and publishes weekly; the next release shows the week the current file cannot see. The number that matters is any single day above zero.

26 August. If the zeros continue, the 30-day average undercuts the November 2024 record on that date, and the worst stretch in the series’ seven and a half years stops being 2024.

A resumption notice. The 10 July suspension was issued without an end date. Its withdrawal would appear in the transit count within days, months before it could surface in any trade statistic.

Correction, 13 October 2026: An earlier version called the 30-day average of 1.1 “today’s”. It is the reading for the 30 days to 9 August, the latest in PortWatch’s data when the piece was published on 15 August.