Hormuz Tracker: U-Turns Surge as Iran Recloses Strait

TL;DR

Shipping through the Strait of Hormuz surged briefly early Saturday before Iran warned of closure via broadcast, prompting multiple freighters to U-turn.
12 commercial ships completed outbound transits that morning per Bloomberg vessel-tracking data, with at least half linked to Iran; inbound limited to 3 carriers.
Closure risks worsening global energy supply disruptions amid US blockade of Iranian ports and fragile ceasefire talks.

The story at a glance

Bloomberg's Hormuz Tracker reports a short-lived rush of ships through the Strait of Hormuz on Saturday morning London time, followed by collapse after an Iranian broadcast declared the corridor closed again. Iran, via its Revolutionary Guard and state media, issued warnings heard by vessels, coinciding with reported gunfire and U-turns by freighters and tankers. This comes a day after Iran's foreign minister said the strait was open for commercial traffic tied to a Lebanon ceasefire, but the US maintains its blockade on Iranian ports.[[1]](https://www.bloomberg.com/news/articles/2026-04-18/hormuz-tracker-widespread-u-turns-take-place-amid-iran-warning?srnd=homepage-canada&embedded-checkout=true)[[2]](https://www.bloomberg.com/news/articles/2026-04-18/iran-broadcasts-to-ships-that-hormuz-is-shut-two-owners-say)

Key points

Traffic briefly surged with 12 commercial ships outbound (at least 6 Iran-linked) and 3 inbound carriers before the halt, per Bloomberg-compiled vessel-tracking data.[[1]](https://www.bloomberg.com/news/articles/2026-04-18/hormuz-tracker-widespread-u-turns-take-place-amid-iran-warning?srnd=homepage-canada&embedded-checkout=true)
Iranian broadcast to ships declared the strait closed to maritime traffic once again, heard by vessels and two owners in the area.[[2]](https://www.bloomberg.com/news/articles/2026-04-18/iran-broadcasts-to-ships-that-hormuz-is-shut-two-owners-say)
Multiple freighters and at least 13 oil tankers, plus LNG carriers from Qatar, performed U-turns after attempting transits.[[3]](https://www.bloomberg.com/news/articles/2026-04-19/hormuz-shipping-traffic-grinds-to-a-halt-as-tensions-deepen)
Owners reported gunfire in the waterway, with one supertanker broadcasting it was under fire; US officials claim at least three IRGC attacks on commercial ships.[[2]](https://www.bloomberg.com/news/articles/2026-04-18/iran-broadcasts-to-ships-that-hormuz-is-shut-two-owners-say)
Reversal tied to US blockade of Iranian ports since Monday, per Iranian state agency Nour; strait now under "strict management and control by the armed forces."[[2]](https://www.bloomberg.com/news/articles/2026-04-18/iran-broadcasts-to-ships-that-hormuz-is-shut-two-owners-say)

Details and context

The Strait of Hormuz, a narrow chokepoint between Iran and Oman, handles about 20% of global oil and significant LNG flows in normal times. Iran briefly reopened it Friday after Foreign Minister Abbas Araghchi's announcement linked to a 10-day Israel-Hezbollah truce in Lebanon, sparking a tanker dash and oil price drop—but hardliners and the IRGC quickly reversed course amid the ongoing US naval blockade.[[4]](https://www.wsj.com/world/middle-east/irans-hard-liners-flex-their-muscle-with-a-u-turn-over-hormuz-f6f70df1)

No commercial transits observed Sunday, grinding traffic to a halt and highlighting Tehran's leverage despite US pressure. This fits a pattern of sporadic openings, toll demands, mine threats, and route restrictions around Iranian island Larak since the US-Iran war escalated in late February 2026.[[5]](https://www.pbs.org/newshour/world/irans-military-closes-strait-of-hormuz-again-citing-u-s-blockade)

Key quotes

Nour news agency: "The strait had gone back to strict management and control by the armed forces," due to the US blockade.[[2]](https://www.bloomberg.com/news/articles/2026-04-18/iran-broadcasts-to-ships-that-hormuz-is-shut-two-owners-say)

Why it matters

The strait carries a fifth of world oil, so disruptions threaten supply chains from Gulf exporters like Saudi Arabia and Qatar to Asia and Europe. Shipowners face higher insurance, delays, and risks, while energy firms and traders deal with volatile prices and rerouting costs. Watch for US boarding actions on Iran-linked vessels or IRGC escalation, though peace talks in Pakistan could shift dynamics if a deal emerges.[[6]](https://bloomberg.com/latest/war-with-iran)