UK Maritime Trade Operations (UKMTO), the Royal Navy-run centre that merchant ships report to in the region, recorded about 20 US-facilitated transits per day through the southern Hormuz route over the seven days to Friday 11 September, against only about 6 per day visible on the Automatic Identification System (AIS), the transponder network that broadcasts a ship's identity and position1. UKMTO reads the three-to-one gap as evidence that much of the traffic is running dark, and says separately that it is aware of facilitated vessels transiting with transponders switched off that it cannot independently verify2.
Total movements still run roughly 90% below the pre-conflict baseline of about 138 vessel movements per day3. Both figures hold at once, and neither can be checked the ordinary way. the strait is far emptier than before the war and busier than its own data shows.
That combination breaks the machinery that prices maritime risk. A war-risk underwriter sets a rate from exposure counts: how many hulls, on what route, for how long. Switch the transponders off and the denominator disappears, so the rate gets set off the worst assumption available rather than off observed traffic. Charterers pass the premium into freight, and freight reaches the consumer weeks later inside the delivered price of a cargo. The one count nobody disputes comes from outside the strait entirely: the International Maritime Organization's confirmed-casualty register, which had reached 75 incidents and 22 seafarer deaths by 10 September. The ships going dark to stay safe are collectively making every cargo dearer, including their own.
