Fewer oil tankers left the Gulf on Tuesday than on any recent day the engine covered.
It was the second low day in a row with data. Another ship was hit near the Strait of Hormuz.
One more low day would meet the test we set on 4 October for a slowdown in oil supply.
Shipping and insurance costs would rise first if the slowdown continues. In the Black Sea, a drone sank a ship off Bulgaria. A Korean company is even testing ships powered by small nuclear reactors.
Our tracking counts tankers leaving the Gulf each day and compares them with the recent average. Days with no data are left out rather than counted as zero.
What could change this. Against this: low counts on two days can reflect routing through shuttle convoys rather than fewer voyages.
So-what: Oil supply from the Gulf may be slowing again, which would push up shipping and insurance costs.
What to watch. Gulf departures; war-risk premiums; Red Sea transits.