How effective is the US blockade of the Strait of Hormuz? That’s the question on everyone’s mind on Tuesday (April 14) after Donald Trump’s pressure tactic to get Iran to the negotiating table came into effect on Monday (April 13).

Now, a day into the blockade, questions over its implementation are being raised as reports emerged that ships are passing through in open defiance of the US. However, Washington noted that no ships “made it past” the United States military blockade in the Strait of Hormuz in its first 24 hours and six merchant ships followed orders to turn around.

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So, what is actually happening in the Strait of Hormuz? Is the blockade as effective as the US claims?

Trump’s blockade of the Strait of Hormuz

After US and Iran talks failed in Islamabad over the weekend, Donald Trump announced that the
US navy would begin a blockade of the Strait of Hormuz. The US president’s move seeks to put pressure on Tehran by targeting two economic drivers — the huge tolls it demands ships pay to pass through the Strait of Hormuz and its oil revenue.

On Monday (April 13), the US Central Command (Centcom) said its forces began implementing the blockade of maritime traffic to and from Iranian ports at 10 am ET (14:00 GMT), in line with Trump’s presidential order.

Centcom said the blockade would apply to “vessels of all nations entering or departing Iranian ports and coastal areas, including all Iranian ports on the Arabian Gulf and Gulf of Oman”.

The US military hasn’t shared more details about the methods it would use to blockade the Strait, with experts suggesting that the most likely option is that the US navy will try to force vessels to change course through threats, and if that doesn’t work, they will launch armed boarding parties to take physical control of the ships.

A map showing the Strait of Hormuz. ReutersUS assessment of Day 1 of Hormuz blockade

After the US blockade of the Strait of Hormuz came into effect, Centcom claimed early success, saying that during the first 24 hours of the blockade, no ships had passed through the vital waterway.

“During the first 24 hours, no ships made it past the US blockade, and six merchant vessels complied with the direction from US. forces to turn around to re-enter an Iranian port on the Gulf of Oman,” wrote Centcom on X. The command added that the blockade is being applied “impartially” to vessels of all nations entering or leaving Iranian ports, while insisting that freedom of navigation continues for ships transiting the Strait of Hormuz to non-Iranian destinations.

More than 10,000 U.S. Sailors, Marines, and Airmen along with over a dozen warships and dozens of aircraft are executing the mission to blockade ships entering and departing Iranian ports. During the first 24 hours, no ships made it past the U.S. blockade and 6 merchant vessels… pic.twitter.com/dpWAAknzQp

— U.S. Central Command (@CENTCOM) April 14, 2026STORY CONTINUES BELOW THIS AD

Centcom added that the
US blockade is being executed with the help of “more than 10,000 sailors, Marines, and airmen, along with over a dozen warships and dozens of aircraft”.

Iranians hold national flags beneath a large billboard reading “The Strait of Hormuz remains closed” as people gather in Tehran’s Revolution Square after the United States and Iran agreed to a two-week ceasefire, on April 8, 2026. AFPTrackers tell a different story

While the US may be touting success with its blockade of the Strait of Hormuz, independent trackers tell a different story.

According to MarineTraffic, four vessels linked to Iran crossed the Strait of Hormuz despite the start of a US naval blockade. However, two of those vessels appear to have reversed course.

According to the ship-tracking data, the US-sanctioned tanker Rich Starry, which is Chinese-owned and Malawi-flagged, sailed from Sharjah in the UAE through the Strait of Hormuz but has since changed direction. Kpler said that the vessel was carrying 31,500 tonnes of methanol and was headed to Sohar in Oman.

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News agency AFP reported that the tanker turned around while in the Gulf of Oman around 1100 GMT on Tuesday and headed back up towards the strait, its destination unknown.

Another ship that sailed through the Strait was Christianna, a Liberia-flagged bulk carrier. It exited the Persian Gulf through the Strait on Monday night, after leaving the Iranian port city of Bandar Imam Khomeini, Kpler said. It said the ship was not carrying any cargo. According to the BBC, this vessel has also turned back.

Elpis, a methanol carrier, traversed the strait roughly around the time that the US blockade began, according to ship-tracking data. Kpler said that the vessel had been at the Iranian port of Bushehr. The United States had placed sanctions on the ship last year under an earlier name, Chamtang, over its connections to the Iranian oil trade.

The BBC also reported that two Iranian-flagged ships had left Iran’s Chahbahar port, which is east of the Strait of Hormuz on Iran’s southern coast, after the start of the blockade. The vessels, Ashkan3 and Shabdis, have both travelled more than 500 km out of Iranian waters.

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Ship tracking data reveals movements of several other vessels in and around the Strait over the last two days. In fact, according to the Wall Street Journal, over 20 commercial vessels have transited through the Strait of Hormuz over the past 24 hours.

This clearly raises questions about the efficacy of Trump’s blockade of the Strait of Hormuz and whether it’s really serving its purpose of pressuring Tehran to end this war.

Passage of ships through Strait of Hormuz

Since the start of the war on February 28, Iran has weaponised the
Strait of Hormuz — the waterway through which 20 per cent of the world’s oil and gas passes. Ship traffic through the Strait of Hormuz has plummeted by more than 95 per cent since the start of the war.

According to ship-tracking data from Kpler, 279 ships are known to have transited the strait between February 28 and April 12, far below the pre-war average of about 100 per day. A ceasefire between the US and Iran took effect on April 8. However, only 45 ships have entered or exited the strait since then.

Hundreds of tankers ‌and other ships have been stranded in the Gulf since the war on Iran began, cutting global oil and gas supply by 20 per cent in the world’s biggest-ever fuel supply disruption.

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With inputs from agencies

First Published:
April 15, 2026, 09:09 IST

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