Strait routing tightened by Iran

Iran has told ships to stop using the usual center lanes in the Strait of Hormuz and follow new routes closer to Iran’s coast because of a mine danger area shown on an official chart released through Iranian media on April 8 and April 9, 2026. The redraw puts commercial traffic nearer to Iranian waters at the same moment Tehran is trying to reopen the strait under a fragile two-week truce. (maritime-executive.com, nytimes.com) The Strait of Hormuz is one of the world’s narrowest energy chokepoints. The International Energy Agency says it is only 29 nautical miles wide at its tightest point, with two shipping channels just 2 miles wide each and a 2-mile buffer between them. (iea.org) That geometry is why even a small routing change matters. The United States Energy Information Administration says about 20 million barrels a day of oil moved through Hormuz in 2024, equal to about 20% of global petroleum liquids consumption, and around one-fifth of global liquefied natural gas trade also passed through it. (eia.gov) Under the long-standing traffic separation scheme, ships normally use internationally recognized inbound and outbound lanes that keep opposing traffic apart like painted lanes on a highway. Iran’s new chart marks the old central scheme as a danger zone and replaces it with corridors that pass near Larak Island and closer to the Iranian side of the strait. (maritime-executive.com, ontimebrief.com) Iran says the reason is naval mines. Reuters reported on March 11, 2026, that Iran had laid about a dozen mines in the strait, and Associated Press reported on April 9 that Iranian semiofficial agencies later published a chart suggesting the Revolutionary Guard had mined part of the waterway during the war. (usnews.com, usnews.com) The legal backdrop is messy because the strait is both narrow and international. Most of the chokepoint sits inside the 12-nautical-mile territorial seas claimed by Iran and Oman, but it is still treated under international law as a strait used for international navigation, where transit passage is not supposed to be blocked. (ontimebrief.com, britannica.com) That is why a routing notice can act like a control lever even without a formal closure. If shipowners feel they must sail under Iranian instructions, near Iranian patrols, and through a mine-risk corridor that Tehran itself defined, then Iran gains practical control over timing, spacing, and who is willing to enter. (maritime-executive.com, nytimes.com) The shipping response has already been cautious. The New York Times reported on April 9 that the number of ships traveling through the strait had dropped, and Lloyd’s List reported on April 8 and April 9 that traffic remained severely disrupted and conditions could change at short notice even after the ceasefire announcement. (nytimes.com, lloydslist.com) Insurance does not make that hesitation disappear. Lloyd’s Market Association said in late March that war cover was still available for Hormuz transits, but Lloyd’s List reported this week that safety concerns, compliance questions, and the structure of war-risk coverage are still shaping decisions by shipowners and charterers. (reinsurancene.ws, lloydslist.com) For cargo owners, that means the problem is not only whether the strait is “open.” A tanker can be technically allowed through and still face delays from rerouting orders, convoy-style spacing, extra security checks, crew reluctance, and higher premiums for a passage that now runs closer to the coast of the country that laid the warning on the chart. (nytimes.com, lloydslist.com, maritime-executive.com) The immediate question is not whether every ship will obey the new map forever. The immediate question is whether enough captains, insurers, and charterers treat Iran’s redrawn lanes as the only safe option, because in a waterway this tight, a “temporary” route can quickly become the real one. (iea.org, maritime-executive.com, eia.gov)