Most tankers in Hormuz sail without transponders as US and Iran release conflicting data

Iran loaded 893,000 barrels a day in July, but by mid-August the volume had slipped to about 156,000, according to Ronin's Grips' open-source intelligence summary published on August 22. A collapse like that should signal an empty strait, but Washington's own count says the opposite.

US Energy Secretary Chris Wright stated in remarks carried by Bloomberg via Fortune on August 16 that around 9 million barrels a day crossed Hormuz last week, nearly half the pre-war flow. Both governments claim control of the same waterway and neither can prove it. Al Jazeera published on August 20, citing Kpler data, that between August 1 and 19, more than 80 percent of tankers carrying crude, LPG, and LNG through the strait—89 out of 112 tracked vessels—sailed with transponders off or on routes nobody can check. The official numbers measure whatever each government wants counted.

The collapse of the Islamabad Memorandum of Understanding was the trigger; it expired on August 17 without a successor after its core promises fell apart within weeks. Ronin's Grips noted on August 22 that the American oil waiver lasted just twenty days and the blockade pause barely twenty-seven. A ballistic missile attack near Emirati waters days later pushed the UAE to freeze all trade with Iran on August 18, cutting Tehran's main offshore banking hub. OilPrice.com reported on August 19 that this was the effect of the freeze.

Yet the shuttle system beneath the headlines is older than the ceasefire’s collapse. Since the spring, producers have run a two-stage operation: short-haul tankers cross Hormuz with AIS switched off, transferring their barrels to long-haul ships waiting off Oman and Fujairah, beyond the range of either navy.

Adnoc, Abu Dhabi’s state oil company, has taken the most hits—23 vessels attacked since the conflict began, with one crew member killed and twenty injured. Despite this, Fortune reported via Bloomberg on August 16 that Adnoc has sold about 135 million barrels of crude worldwide since June and continues to issue new tenders, while OilPrice.com's August 20 headline tally tracks the attacks. Lloyd's List Intelligence reported on August 19 that Adnoc Logistics & Services recently disclosed acquiring six very large crude carriers and five very large gas carriers for $1.3 billion total, paying above usual secondhand prices and, in effect, buying sovereignty over its logistics.

Iraq, Qatar, and Kuwait use the same dark corridor for lack of spare pipelines. Iran operates the mirror image: its Persian Gulf Strait Authority demands permits and tolls paid in cryptocurrency while its forces attack ships refusing to pay, Ronin's Grips reported on August 22.

For Gulf producers, every dark transit is revenue that survives a war. As Fortune noted on August 16, Brent holding between $80 and $90—rather than the $150 feared at the war's outset—shows the market paying them to take risk. For Iran, the permit-and-toll regime turns geography into cash and leverage even as its exports fall: Ronin's Grips reported on August 22 that untraceable barrels rose from 5 percent of its shipments during the truce to 66 percent or higher afterward. For Washington, the blockade hits Iranian ports, letting compliant-but-dark non-Iranian cargo provide pressure on Tehran without choking the world. Each actor relies on the darkness the other side created.

The satellite evidence is clustered off Oman. The EU's Sentinel-1 satellite radar shows about 150 ships, from crude carriers to bulkers, anchored compared to around 40 in January; many wait to receive cargo from shuttles that crossed the strait in silence, according to Bloomberg via Fortune on August 16. Satellite radar is indifferent to transponders. When official transit counts fall, the anchored fleet grows, and that gap marks the real volume.

The trade reorganized

During the Tanker War from 1984 to 1988, Iran and Iraq attacked hundreds of merchant ships in the same waters, but the trade reorganized instead of stopping, rerouting around reflagged fleets. Kuwaiti tankers sailed under US flags escorted by the US Navy in Operation Earnest Will, freight rates jumped, but flows continued. Now, none of the navies can escort what they cannot see. Ships evade both sides at once, and what replaced visible state protection in the 1980s is sheer invisibility.

The counter-case runs the other way too. In the Red Sea after 2024, dark routing did not bring ships back to Suez; volumes simply pivoted to the Cape route. Hormuz has no such fallback—pipelines through Saudi Arabia and the UAE only carry some of the flow—so here the dark fleet doesn't evade the chokepoint, it preserves it.

Freight, hulls and slicks

Start with freight: Lloyd's List Intelligence reported on August 19 that rates from the Middle East Gulf to China have soared above $520,000 a day for the largest crude tankers, driven by owners demanding war pay.

Next, the fleet itself is contaminated. Thirty shadow-fleet tankers and gas carriers that once carried Iranian cargoes have lifted compliant cargoes since the war began, including at least four very large gas carriers out of the UAE and Qatar—before this war, such vessels hardly ever returned to mainstream trades, Lloyd's List Intelligence noted on August 19. A charterer fixing a ship today cannot know for certain what the hull carried last year, and US secondary-sanctions scrutiny travels with the hull.

Then the sea. Three oil slicks are spreading through the Persian Gulf and off Oman, one reaching Qeshm Island's mangroves.

Another slick appeared off Muscat with no known source—a sign of an anonymous transfer gone wrong, according to the New York Times on August 21 and Bloomberg on August 16.

Absorbing this are the crews and coastal towns. Seafarers have died making the crossing; one bulk carrier was struck fatally during the week of August 10 with no claim of responsibility. Lloyd's List Intelligence reported on August 19 that DP World is burning about $100 million each month to keep the Jebel Ali terminal ready for reopening, while it operates at a tenth of normal throughput, with volume shifting to Fujairah and Oman. The profits, meanwhile, collect further upstream. National oil firms with their own ships, tanker owners collecting record spot rates, and traders reading satellite radar while others cling to press releases.

Confirmation would come if Lloyd's List Intelligence revised its transit counts upward as new dark passages are recognized—it already acknowledges on August 19 that its own numbers will rise—and as the anchored fleet off Oman grows further. The case would be broken by a strike on a shuttle-transfer anchorage or a US interdiction of dark transits regardless of cargo; either would turn the workarounds into targets and force trade onto pipelines alone.

Hormuz is neither closed nor reliably open. It is a waterway whose real traffic exists in satellite radar images and insurance balance sheets, priced at half a million dollars a day, paid in ships and mangroves, while governments argue over figures neither side can see.