US warns commercial ships to steer clear of Iranian territorial waters

The U.S. Maritime Administration has issued a formal advisory urging American-flagged commercial vessels to avoid Iranian territorial waters in the Persian Gulf and Strait of Hormuz. The warning, effective for six months, advises ships to stay as far from Iran's territorial sea as safely possible and recommends transiting close to Omani waters when eastbound through the strategic chokepoint.

Specific risks and recommended procedures

The advisory states that commercial vessels have long faced risks of being hailed, queried, boarded, detained, or seized by Iranian forces in these waters. It provides specific protocols: if hailed, vessels should provide their name and flag state while asserting they are proceeding in accordance with international law. Ship masters are advised to decline boarding requests if safe to do so, citing the Law of the Sea Convention, but crews should not offer forcible resistance if a boarding occurs.

Technical guidance and regional context

The U.S. agency also recommended that vessels keep their Automatic Identification System (AIS) transponders active, noting that Iran has previously cited the absence of an AIS signal as a justification for seizures. The advisory reflects significantly heightened tensions between Washington and Tehran, coinciding with an increased U.S. military presence in the region. The guidance is aimed at mitigating the risk of incidents that could escalate into broader conflict.

Impact on global shipping and security

The Strait of Hormuz is a critical global oil transit route, making security advisories here particularly consequential for international trade. The U.S. warning underscores the persistent volatility in Gulf waters and the operational challenges for commercial shipping navigating between geopolitical rivalries. Such advisories influence insurance rates and routing decisions for global carriers operating in the region.