Vessel traffic through the strait of Hormuz on the US-assisted southern transit route stopped completely in the past day following increased Iranian attacks on vessels at the start of the week.
Out of the 10 vessels that transited the strait of Hormuz on 21 July, eight vessels took the Iran-favored northern transit route, while two vessels transited through the center transit lane where most traffic passed before the war, data from vessel tracking service Windward shows.
Vessel traffic through the center transit lane has been uncommon since the breakout of the war because of suspected Iranian-placed mines throughout the area. Commercial traffic through the strait of Hormuz since the outbreak of the war on 28 February has been bifurcated between the northern route, which runs along the Iranian coastline, and the southern route along the Omani coast.
Transits through the US supported southern traffic lane has been steadily falling following the reprisal of attacks between the US and Iran and slowing traffic through the strait.
On 20 July down only two vessels out of 15 that transited the strait used the southern transit lanes, according to Tradewind data. This is down sharply from 24 June, the day when vessel transits through the strait of Hormuz reached their highest since the signing of the US-Iran memorandum of understanding that temporarily stopped the fighting, with 25 out of the 41 outbound vessels transiting the strait doing so on the southern lane.
The UK Trade Maritime Organization (UKTMO) reported three attacks on tankers transiting through the strait of Hormuz between 20 and 21 July, all occurring in the southern transit lane.
Centcom did not respond to a request for comment on whether the US was still offering assistance for commercial vessels looking to transit via the southern lane.
Iran amps up Hormuz rhetoric, operations
Iranian politicians on Wednesday reaffirmed their commitment to controlling the strait of Hormuz, likely in response to President Donald Trump's vow to bomb Iranian power plants and bridges every time Iran strikes commercial ships in Hormuz.
The Iranian Revolutionary Guard Corps (IRGC-N) reiterated its position that it controls the strait of Hormuz via a social media post on X today.
"The input and output of the strait of Hormuz are specified and under our definitive control," the IRGC-N said. "Alternative routes are unsafe and dangerous; we warn against their use, as it will have severe and irreparable consequences."
"We have repeatedly said that the situation of the strait will not return to pre-war conditions," said Iranian parliamentary speaker Mohammad Bagher Ghalibaf, who headed previous negotiations with the US, in a 22 July post on X.
Iranian actions to control traffic in the strait are also evolving. Satellite imagery shows the tanker Kavomaleas, part of Greek shipowner Dynacom's fleet, has been seized by Iran and brought to Iranian waters near Larak. The vessel was attacked by Iranian forces on 20 July, with the crew confirmed safe, according to UKTMO. This is the first reported instance of a vessel attacked by Iran in the strait of Hormuz getting escorted into Iranian waters.
"A large IRGC fast in-shore attack craft presence plus one small craft positioned directly alongside the tanker is assessed consistent with an escorted move toward Iranian waters rather than an uncontrolled drift," Windward said.
