Strait of Hormuz Daily Transit Monitor

What counts as a transit. One commercial vessel crossing the narrows, established from satellite AIS position tracks. Every voyage between the Persian Gulf and the open ocean has to cross the same line, so the yardstick never moves. Sitting near the narrows, queueing at anchor, or entering the approaches and turning back all score nothing.

One ship, one count. Once a vessel crosses, it cannot count again for 48 hours, however many times it recrosses: a slow multi-day passage or a ship loitering on the line is one transit, not five. The whole history back to 2019 is built on that one rule, which is what makes today comparable with any day before it.

Classification. Each vessel is classed tanker, cargo or other from the ship type it broadcasts, so the tanker split reads the crude story specifically.

Coverage honesty. A day where the listening gate heard less than 12 hours of live signal is recorded as a gap, never as zero transits: silence is a measurement problem, and this dataset refuses to dress it up as an empty strait.

A fixed pre-crisis norm. The comparison baseline is the median of the twelve months ending the day before the closure was declared, and it does not move. A rolling norm would sink toward the disruption the longer it lasted, so a strait running at one percent of normal would slowly appear to recover while nothing changed at sea.

The count is a floor, not a total. Every figure here comes from vessels that were broadcasting. Through mid-2026 a large share of tanker transits have crossed with transponders switched off, and trackers working from other evidence count more hulls than any AIS-derived series can see. Read this as the minimum that moved, and read the trend rather than the level.

Our own gate. Helious also runs an independent terrestrial AIS gate across the narrows, built to give a same-day count. Terrestrial receiver coverage over the Gulf is absent at present, so it contributes no readings today and this page falls back to the weekly satellite record. Any day it does measure is labelled as measured live.

How many ships pass through the Strait of Hormuz each day?

Before the closure the strait carried a median of about 73 commercial transits a day. On 2026-08-09, the latest measured day, Helious counted 1 transit, of which 0 were tankers.

Why has the count not changed for several days?

The measured transit record publishes weekly, on Tuesdays, carrying data through the preceding Sunday. Between publications the latest measured day stays the same and can run up to nine days behind, which is why every figure here is stamped with the day it measures and how old that day is. A repeated number means no new measurement has been published, not that nothing moved at the strait.

How is the transit count measured?

A transit is one commercial vessel crossing the narrows, established from satellite AIS position tracks. Each ship counts once per 48 hours however many times it recrosses, and is classified as tanker, cargo or other from its broadcast ship type. Sitting near the narrows or queueing at anchor counts for nothing. Because the count only sees vessels that are broadcasting, and a large share of tanker traffic now crosses with transponders off, read it as a floor rather than a total. Helious posts the reading to its terminal twice a day, 8:30am and 3:30pm ET.

Have the vessels in the live Gulf count passed the strait?

No. The live line is a regional activity gauge: every vessel underway anywhere in the Persian Gulf box over the last 30 minutes, refreshed continuously. A ship in that count may be working between Gulf ports and may never approach the narrows. Nothing joins the transit count without crossing the measurement line inside the strait itself.

Why does the daily count matter for markets?

Roughly a fifth of the world’s oil moves through the strait. Fewer tankers means less carried crude reaching the market: upward pressure on oil, stickier inflation, a bearish input for bonds and a higher-for-longer rate headwind for equities.

Can I use this data?

Yes. The dataset is free to cite, download (CSV/JSON) and embed for any purpose with a link back to this page.