Around 1,000 vessels carrying up to 20,000 seafarers are currently unable to transit the Strait of Hormuz due to the threat of Iranian attacks on commercial vessels.
The International Maritime Organization (IMO) said traffic through the narrow channel has collapsed by about 90 percent compared with normal levels, with 3,000 commercial ships still within the wider Arabian Gulf.
The UN shipping regulator said it was “aware of some 1,000 affected vessels with approximately 20,000 seafarers” that are currently unable to pass through the strait.
Geolocation data suggests scores of ships are now backing up or loitering near the entrance to the chokepoint, as operators wait for clarity on the security situation.
“We are seeing hundreds of vessels in the Gulf or just outside the Strait of Hormuz right now,” said Saleem Khan, chief data and analytics officer at Pole Star Global.
The maritime intelligence company said 2,474 commercial vessels, including 178 crude oil tankers, “have not moved” in the Arabian Gulf since March 5.
Ships are either remaining at berth or anchorage inside the Gulf, or gathering outside the entrance to the bottleneck rather than attempt to pass through, Khan said.
Speaking on March 9, IMO secretary-general Arsenio Dominguez expressed “grave concern regarding the recent attacks on merchant vessels in the region of the Strait of Hormuz, which have resulted in at least seven fatalities and several injured seafarers”.
Dominguez reiterated his call for shipping companies to “exercise maximum caution” when operating in the affected region.
Roughly 20 percent of global oil supply normally passes through the strait, making it one of the most strategically sensitive maritime waterways in the world.
Data compiled by Pole Star Global and Clearwater Dynamics shows at least 17 reported incidents involving commercial vessels since the conflict began on February 28.
They note that some claims circulating on regional channels – including reports attributed to Iran’s Islamic Revolutionary Guard Corps – could not be independently verified.
Their analysis reveals that oil tankers account for the majority of vessels involved, with nine of 17 identified ships falling into that category. Four people have been confirmed killed with three crew still missing.
Khan said he had also observed vessels switching off their Automatic Identification System (AIS) transponders and reappearing elsewhere in the Gulf hours or days later.
“This is normal in a conflict zone and is meant to evade detection from hostile forces,” he said.
However, several vessels which left the region shortly before the war have also broadcast unusual AIS destination messages, including signals identifying themselves as Chinese-owned ships.
Khan said such signals can be used by vessels to indicate ownership or nationality in an effort to reduce the risk of attack or seizure while operating in contested waters.
Meanwhile, the Trump administration has announced a $20 billion maritime reinsurance programme aimed at reviving shipping through the strait.
The US International Development Finance Corporation said last week that it would deploy maritime reinsurance – including war-risk cover – across the Persian Gulf region to stabilise commercial trade.
The facility, which initially applies only to vessels, is intended to insure losses on a rolling basis.
The announcement follows comments by President Donald Trump, who ordered the agency to offer insurance “at a very reasonable price” to help maintain the flow of energy and other commercial trade through the Gulf as oil prices surge.
Some governments had warned that a lack of war-risk insurance was discouraging shipping companies from transiting the strait.
President Trump has also suggested the US military could escort vessels through the waterway, although no formal plans have yet been announced.


