Iran-linked ships slow or stop as US blockade is ‘fully implemented’

The US Navy blockade of Iranian ports appeared to be working Wednesday, with no Iran-linked ships visibly able to leave the region since the blockade took effect 48 hours earlier, according to U.S. authorities and vessel-tracking firms.

Several vessels appear to have stopped or slowed after exiting the Strait of Hormuz into the Gulf of Oman, “which may reflect the deterrent effect of the blockade,” Kpler, a maritime data company, noted in a report Wednesday.

Still, the data is likely incomplete because of how difficult it is to track the location of ships in waters in and around the strait. While most commercial vessels are required to travel with transponders that transmit a ship’s name, location and other identifying information, many vessels in the Persian Gulf are hiding their location or falsifying other information, making real-time ship tracking difficult, according to experts.

Adm. Brad Cooper, the US Central Command leader, said late Tuesday that the blockade had been “fully implemented” and had “completely stopped” commercial traffic to and from Iranian ports. More than a dozen Navy warships are patrolling waters east of the strait, enforcing a blockade on all vessels from all nations entering or leaving coastal areas or ports in Iran.

Central Command on Wednesday said nine vessels had complied with directions to turn around and reenter an Iranian port or coastal area, though it did not give details. Kpler, which also uses satellite data to track ships when their location looks like it may have been falsified, said two ships with links to Iran and subject to US sanctions appeared to have made U-turns. Eight additional ships that have historically carried Iranian cargo were stationary in the Gulf of Oman or were slowing down, according to Ana Subasic, an analyst at Kpler.

One of the ships that reversed course, the Rich Starry, a Chinese tanker under US sanctions, was traveling eastward through the strait Tuesday before turning around. The other ship, the Ostria, was heading toward an Iranian port and was turned back before it could pick up cargo, most likely of Iranian refined products.

Subasic said there had been no loadings at Iranian ports since the start of the blockade Monday. “What you’re seeing with the US blockade is they’re trying to stop Iranians from lifting their cargoes, but at the same time getting out as many vessels as they can on the US side.”

President Donald Trump, in announcing the blockade, said the Navy would encourage ships not linked to Iran to transit the strait. More than a dozen ships without links to Iran moved through the strait Monday and Tuesday, according to Central Command and tracking firms like Kpler, staying close to the Omani coast and keeping the most distance from possible sea mines in the middle of the waterway.

Traffic around the strait remains at a fraction of its usual levels, and the effects have rippled through the global economy. Since the blockade came into effect, traffic has slowed further, with shipping companies unwilling to risk the crossing.

Nils Haupt, a spokesperson for German shipping company Hapag-Lloyd, which has six vessels and 150 seafarers stranded in the Persian Gulf, said the situation was still too uncertain to make plans for the company’s ships to exit the Gulf.

He said the company was concerned about the risk of sea mines. Hapag-Lloyd was also still waiting for assurances that its ships would not be targeted by Iran and for answers from US authorities on the order in which stranded ships were supposed to exit the strait.

“We would need security guarantees for the crew, the vessel and the cargo transported,” he said in an email Wednesday.