Washington says thirty ships a day cross Hormuz. Ship trackers can count eight.

Al Jazeera reported on 3 September, citing the marine analytics firm Kpler, that six vessels crossed the strait on Wednesday, 11 on Tuesday and five on Monday, putting the ten-day average at 13 vessels a day, with other tracking services showing a similar pattern. The same piece noted that President Trump says the United States is helping around 30 ships cross the waterway daily, and that ship-tracking data suggests the number is far fewer. Windward, an Israeli maritime AI firm, logged only eight transits in the 24 hours to 3 September — four inbound, four outbound — of which five broadcast no AIS signal at all, including a VLCC that surfaced briefly from an eleven-day blackout before going dark again on entering the strait. The independent reader-funded tracker straits.live, whose page was live on 5 September, records six transits on 30 August against a pre-war norm of roughly 85 a day, and answers its own question — is the strait open? — with “effectively no”.

The blockading side publishes different arithmetic. United Against Nuclear Iran, a Washington advocacy organisation campaigning for pressure on Tehran, relayed on 3 September figures from the Joint Maritime Information Center, a US-led coalition body: 877 vessels transiting since 18 June, 1,490 since the war began, with 54 transits on 24 June the highest single day of the conflict. Its 1 September edition put US enforcement at 84 commercial vessels redirected, three disabled for non-compliance and two boarded. Both the compiler and the underlying source are parties to the argument. Overlaying all of it is MARAD advisory 2026-006 of 26 March, which strongly advises US-flagged vessels in the Red Sea, Bab el Mandeb and Gulf of Aden to switch off their AIS transponders — a US government instruction to become invisible to the same systems now being used to score the blockade.

Assessment: Nobody in this dispute is counting the same thing. Kpler and Windward count what transponders broadcast; the JMIC counts what a navy sees; the White House counts escorts offered rather than voyages completed. Windward’s finding that five of eight ships went dark means the low numbers are themselves floors, not ceilings — and MARAD has been telling merchant masters to go dark since March. The honest read is that the strait is functioning at a small fraction of normal volume and that the true fraction is unknowable from open sources. That is precisely the condition in which a president can tell an Oval Office audience, as Trump did on 4 September, that the United States has “essentially” taken over Iran and that Iran is “small potatoes”. Ask for the methodology before accepting either figure.