Iran has reportedly mined the deeper waters in the southern stretch of the Straits of Hormuz to force traffic to sail close to the northern shore, as traffic partially resumes under an informal permit system.

The mines have been laid by the Iranian navy as a way of further controlling the limited traffic that is now starting to pass through the straits, which puts vessels in easy range of its drones, missile and naval drones. At its narrowest point, the Straits are only 34km wide.

Bulk carriers sailing eastbound to exit the Middle East Gulf are seen re-routing through Iranian waters over the past 48 hours as they navigate through the Strait of Hormuz, one of the first signs of a workaround in the region, Windward reports.

Windward tracked at least five ships over March 15 and 16 leaving via a route that takes ships well within Iran’s territorial waters, circumventing shorter, normal two international navigation channels in the middle of the straits.

After the IRGC shut down the straits on March 2, traffic is resuming slowly after Tehran introduced an informal permits-for-passage system that allows tankers from “friendly countries” to pass after they have been stopped for inspection.

US President Donald Trump has promised to reopen the Straits by providing naval escorts, but the US navy has refused all requests so far, as the straits are “too dangerous to traverse.”

Notably, Greek media reports that the US’ two flagship battleships, the USS Gerald R. Ford and the USS Abraham Lincoln, have left the Gulf. The USS Gerald R. Ford is due to return to port in Crete next week.

This week, Trump ordered more of the navy to steam to the Gulf, including the USS Tripoli that is carrying 5,000 Marines and landing equipment, which will arrive at the end of the month. In addition, he called on other navies from Europe and even China to join the US flotilla, but they have all declined.

Straits are partially open

The permits system has partially reopened the straits to traffic and oil is beginning to leave for international markets – almost exclusively Asia.

A total of around 8mn b/d of oil is now being exported from the Gulf, according to bne IntelliNews estimates. By far the largest share is 6.5mn b/d from Saudi Arabia’s westward pipelines. The piped oil is not a separate export route, but simply an emergency fall back the Saudis built for just this eventuality. The oil it is exporting by pipeline would have left by ship via the Straits of Hormuz in normal times.

Iran oil tankers carrying some 1.5mn b/d have been transiting the straits uninterrupted throughout the conflict and are earning Tehran some $150mn a day, according to the Financial Times.

All the oil leaving Hormuz has been bound for customers in Asia, with the majority going to China.

A Greek shipowner sent a second oil tanker through the Strait of Hormuz on March 14, bucking caution among the shipping industry. The Smyrni, run by Athens-based Dynacom Tankers Management Ltd., signalled its location off Mumbai on March 14, digital vessel-tracking data compiled by Bloomberg show. The vessel’s previous signal was inside the Persian Gulf, meaning it likely turned off its transponder during transit.

The Indian Navy just escorted two LPG tankers – the state-owned Shivalik and Nanda Devi - through the Strait of Hormuz under Iranian permission on March 17.

They crossed after Prime Minister Narendra Modi called Iran’s acting president and India’s External Affairs Minister Subrahmanyam Jaishankar held three separate conversations with Iranian Foreign Minister Abbas Araghchi. A third Indian tanker remains in the Persian Gulf under naval warship protection. Twenty-two Indian vessels had been stranded west of the strait.

Despite the Indian naval escort, ships still require insurance, but the prices have skyrocketed. After P&I clubs cancelled Gulf war-risk extensions on March 5, single-voyage cover is available at 1-5% of hull value. For a state-owned vessel, government indemnity can substitute.

The Hormozgan provincial IRGC naval command, running Hormuz under Decentralized Mosaic Defence doctrine (DMD) standing orders without needing Tehran’s approval, verified the vessels by radio hail and Automatic Identification System (AIS) transponder signal.

The volume of oil departing is expected to rise, but will be severely restricted by the onerous new bureaucracy imposed by Tehran’s permits system. Windward reports, eight ships, excluding Iranian flagged vessels, were tracked through the strait with their AIS on March 16, nearly double numbers seen earlier this week. Pre-war over 100 ships would traverse the Straits a day unimpeded by any bureaucracy.

Tehran is at the same time closing down another alternative UAE route, a pipeline from its oil fields to its short strip of coast on the open water side of the Hormuz at the port of Fujairah on the Gulf of Oman. The pipeline has a capacity of 1.5mn b/d, which has come under missile attack and is reportedly closed now. So far, the Saudi by-pass pipeline that terminates on the Red Sea has not been attacked.

Iran also has the option of closing down the Straits of Bab al-Mandab at the entrance to the Red Sea, by appealing to its allies, the Yemeni Houthis. The rebels are reportedly harassing passing ships for bribes but have not halted the flow of traffic so far.