Vast ship clusters, speeding tankers point to Strait of Hormuz jamming amid Iran conflict

Published Tue, Mar 10, 2026 · 01:28 PM

AT LEAST a dozen clusters of ships have appeared near the Strait of Hormuz, a likely sign of elevated electronic interference around the waterway that’s central to the US and Israeli war against Iran.

The groups, which can number more than 200 vessels for some clusters, contain ships of all types, with some that appear to be travelling at more than 100 knots an hour, according to tracking data compiled by Bloomberg.

The maritime artery is a key focus for investors at present because its effective closure during the conflict has thrown the global energy market into disarray, forcing Persian Gulf producers to lock-in oil output as storage capacity runs out.

The halt to normal flows initially lifted Brent futures toward US$120 a barrel, although contracts fell sharply on Tuesday after US President Donald Trump signalled that the war may soon end.

“Over the past 48 hours, the situation has become ‘impenetrable’, said Mark Douglas, a maritime-domain analyst at Starboard Maritime Intelligence. Trying to tell where any vessel is around the strait with tracking data is all but impossible, he added.

Some of the clusters appear to form distinctive shapes, including an apparent circle of vessels inland near Abu Dhabi, and one in the form of an inverted “Z” off Ruwais in the United Arab Emirates, the data showed on Monday.

Other groups are in the Gulf of Oman, possibly indicating vessels waiting in groups for tensions to ease, or secure clear loading dates, before entering Hormuz.

The odd arrays of vessels point to ships’ navigational systems being interfered with by electronic jamming, making them appear on tracking platforms away from their actual locations. Such practices often spike at times of heightened geopolitical tensions, as militaries engage in electronic warfare.

The jamming can distort vessels’ reported speeds. The Asprouda, a 2013-built products tanker, signalled on Monday that it was travelling at an improbable 102.2 knots off Jebel Ali, equivalent to almost 190 kmh. Such tankers typically have a maximum speed of about 16 knots.

The appearance of the huge groups of vessels stands to compound nervousness for shipowners and charterers of operating in the region.

As the conflict has dragged on, the industry has already faced escalating war-risk insurance premiums, with several vessels targeted by missiles and projectiles.

Jamming began immediately at the outset of the conflict and impacted more than 1,100 ships in the Persian Gulf, according to the maritime-intelligence firm Windward. Traffic through Hormuz totalled just five vessels on March 4, compared with 120 crossings on Feb 26, according to Windward.

President Trump has floated the possibility the US could offer insurance for vessels and Naval escorts in a bid to revive maritime traffic through Hormuz, which links the Persian Gulf to global markets.

He has also told CBS he was “thinking about taking it over,” although it was not immediately clear what specific actions the president was contemplating.

“Any vessel navigating the area clearly can’t rely on GPS,” said Douglas at Starboard Maritime, referring to the global positioning system. That “compounds the security situation in which vessels have been struck,” he said. BLOOMBERG