Most tankers crossing Hormuz go dark as U.S. and Iran impose dueling blockades

Between August 1 and August 19, when Kpler analysts counted every crude, LPG and LNG carrier crossing the Strait of Hormuz, just two of 112 sailed it openly, Al Jazeera reported on August 20. Twenty-one took Iran's northern route. The remaining eighty-nine went dark, transponders off, routes unclassified, and the satellites caught them doing it.

Since May the United States Navy has run a nightly convoy of up to twenty tankers down Oman's coast under fighter jets, helicopters and warships, moving as much as ten million barrels of Gulf oil out past Iran, as The Telegraph reported on August 20. That is the route Washington protects and publicizes. The escorted shuttle is the story Washington tells; the dark fleet is what the imagery shows.

The trigger is the collapse of the June 17 memorandum of understanding between Washington and Tehran, which expired on August 17 without a final deal and put the American blockade of Iranian ports back in force, United Against Nuclear Iran reported on August 19. Since the war began on February 28, Iran has closed the strait, attacked the ships that use it, and demanded approval for every transit, while the United States has answered with its own blockade and its own corridor. Two navies now claim the same water, and the shipowners are choosing neither.

Tehran wants every hull to ask permission because the queue is its last bargaining chip; if the strait flows without Iran, its bargaining power sails away with it, as Chatham House's Neil Quilliam put it plainly in Al Jazeera on August 20. Washington wants barrels moving on the southern route under its flag of protection, proof the strait cannot be closed by anyone else.

The Gulf exporters, Adnoc chief among them, want their cargoes out alive. The company says Iran has hit fifteen of its vessels with missiles and drones since the war started, killing one crew member and wounding twenty, Al Jazeera reported on August 20. The shipowners want to survive the crossing and get paid, and they have concluded the cheapest life insurance is a switched-off transponder.

The dark transits

A tanker loads at a Gulf terminal, kills its AIS, runs one of the two routes with no digital footprint, meets a long-haul vessel at a ship-to-ship transfer point off Oman or Fujairah, passes the cargo across, and returns to port unseen. Saudi Arabia, Iraq and Kuwait have all used the pattern, Al Jazeera reported on August 20, and so, for different reasons, has Iran, which re-paperits barrels as Omani exports to slip the American blockade. The dark ships belong to everyone.

Lloyd's List Intelligence puts numbers on it. Preliminary counts show seventy-three transits between August 10 and 16, down from ninety-one the week before, and the firm expects the figures to rise as more dark voyages are identified after the fact, it said on August 19. The gap between the official count and what the imagery finds is the real measure of the strait.

Before the war, roughly one hundred and thirty ships crossed every day; in nineteen days of August, two hundred and thirty-six crossed in total, Al Jazeera reported on August 20. The strait is a quarter of itself, and most of what moves, moves invisibly.

In the Tanker War of the 1980s, Iran and Iraq hunted each other's shipping and Kuwait's tankers sailed under American flag in Operation Earnest Will, the largest convoy effort since the Second World War. Then, as now, escort made the route and darkness made the rest. What is different this time is who is hiding: in 1987 the dark ships were the sanctions-busters and the flagged convoys were respectable. Now Adnoc itself runs dark shuttles, a national oil company of an American ally borrowing the tradecraft of the sanctioned, and Lloyd's List Intelligence noted on August 19 that the practice was almost unheard of before the conflict.

The escorts matter anyway. CentCom counts about one thousand three hundred vessels helped through the strait since May, carrying some six hundred and sixty million barrels, Gulf News reported on August 21. Freight is flowing, and TD3C earnings on the Middle East Gulf to China route have climbed above five hundred and twenty thousand dollars a day, according to Lloyd's List Intelligence on August 19. But the missile that hit the Adnoc tanker on August 8, fired even as Oman and Iran were finalising a negotiated shipping arrangement, showed what an escort cannot stop, according to Political.org on august 8. A convoy defends a route rather than the sea around it.

Who pays and who profits

First, the owners willing to cross are few, so they name their price, and the national oil companies pay it. Adnoc Logistics and Services has bought six very large crude carriers and five gas carriers for a combined one point three billion dollars, several secondhand hulls priced well above normal valuations, Lloyd's List Intelligence reported on August 19.

Second, the shadow fleet is bleeding into the legitimate trade. Thirty non-sanctioned vessels that once carried Iranian cargoes have lifted compliant cargoes since the war began, including five very large crude carriers, and four gas carriers with Iranian LPG histories loaded in the UAE and Qatar in recent weeks, the firm said the same day. A buyer of a Gulf cargo today cannot fully know whose steel delivered it yesterday.

Third, the darkness is becoming its own hazard. The Caroline Bezengi, damaged and trailing an oil slick off Oman, shows up in satellite imagery as a warning of what untracked, overloaded traffic means in a crowded war zone: collisions and spills that cannot be traced to a responsible owner, according to The New York Times on august 21. DP World is spending about one hundred million dollars a month keeping Jebel Ali ready while the port runs at a tenth of normal container volume, and building up Fujairah specifically to bypass the strait altogether, according to Lloyd's List Intelligence on August 19. The infrastructure of avoidance is being financed into permanence.

Asian refiners pay, through Brent at about ninety-three dollars against sixty-six before the war, as Al Jazeera reported on August 20.

Seafarers pay too. One was killed this week when a bulker was struck, Lloyd's List Intelligence reported on August 19, and no group claimed it.

The winners are the few owners still willing to cross, collecting half-million-dollar days, plus the satellite and analytics firms whose imagery is now the only honest map of the strait. The state that profits most never has to fire a shot. Iran keeps its grip on the queue as long as most ships fear its missiles more than Washington's blockade, and a fifth of energy traffic still openly sails its route, Al Jazeera noted on August 20.

The read confirms if next week's imagery shows the dark share holding above four-fifths while the escorted convoy keeps its schedule, and if Lloyd's List Intelligence keeps revising its transit counts upward as hidden voyages surface.

It breaks if an Omani-Iranian management deal puts both navies on one registry of approved transits, or if a massed strike closes the strait outright and turns the dark fleet into a stranded one. The satellites, not the press conferences, will settle which.