What is really moving through the Strait of Hormuz?

The United States says its forces are escorting dozens of commercial ships through the Strait of Hormuz and helping move millions of barrels of oil each day. Ship-tracking firms, however, recorded between five and 11 crossings on the latest three reported days, with a 10-day average of 13 vessels.

Iran says it remains in control of the strait and that only pre-approved vessels using designated channels can pass safely. The competing accounts reflect different definitions of which vessels count, as well as gaps created when ships switch off their tracking systems.

What Washington and Tehran are saying

Donald Trump has said the United States is in “total control” of the waterway and later said it was under US control. US officials also say CENTCOM has cleared transit lanes of sea mines. The claims come after the waterway was closed when the US-Israel war on Iran began six months ago, according to the supplied account.

Iranian Parliament Speaker Mohammad Bagher Ghalibaf said some ships had crossed but maintained that Iranian forces remained in “complete control”. He warned that vessels using what Iran considers an illegal southern route could be targeted. The Islamic Revolutionary Guard Corps separately said two oil tankers were disabled by mines while using such a route. For additional context, see “Why the Strait of Hormuz crisis is reshaping global shipping”.

Key figures

• US officials told CNN that 40 commercial ships carrying about 18 million barrels of oil crossed on Tuesday under US military escort.
• Donald Trump said the US Navy was helping about 30 ships cross each night; Treasury Secretary Scott Bessent cited 10 million to 17 million barrels moving on reported days.
• Kpler recorded six crossings on Wednesday, 11 on Tuesday and five on Monday, while Lloyd’s List Intelligence recorded about 12 daily transits from August 26 to September 1.
• Before the war, around 100 ships and 20 million barrels of oil were estimated to pass through Hormuz each day.

Why the numbers do not match

Marine analytics firm Kpler counts vessels that meet its tracking criteria, while Lloyd’s List Intelligence counts cargo-carrying vessels above 10,000 deadweight tonnes. US operational figures may also include naval auxiliaries, offshore support vessels, tugs, coastal craft and dhows moving under or near military protection.

The United States can draw on satellite, airborne and other sensor coverage, along with convoy manifests, to identify movements that automatic identification system tracking does not immediately show. Some ships have switched off their transponders, leaving crossings classified as “dark” or unknown and requiring later revisions. A related part of this story is covered in “Iran and Oman weigh a temporary shipping route through Hormuz”.

The Joint Maritime Information Center said on September 1 that commercial traffic remained far below its peacetime baseline despite a modest increase from recent lows. It rated the risk to shipping as severe because of the continued possibility of drifting or uncharted mines, despite the US claim that the lanes had been cleared.