The US Maritime Administration (US MARAD) has issued an advisory warning U.S.-flagged commercial vessels transiting the Strait of Hormuz and Gulf of Oman.
Commercial vessels transiting the Strait of Hormuz and Gulf of Oman have long been at risk of being hailed, queried, boarded, detained, or seized by Iranian forces. Iranian forces have historically utilized small boats and helicopters during boarding operations and have attempted to force commercial vessels into Iranian territorial waters, including as recently as 3 February 2026.
The U.S. government is continually assessing the maritime security situation in the region to identify and differentiate threats and safeguard freedom of navigation, ensure the free flow of commerce, and protect U.S. vessels, personnel, and interests.
Guidance
If hailed by Iranian forces, U.S.-flagged commercial vessels should provide vessel name and flag state and affirm that they are proceeding in accordance with international law as reflected in the Law of the Sea Convention.
If Iranian forces seek to board a U.S.-flagged commercial vessel navigating these waters, the vessel’s Master should, if the safety of the ship and crew would not be compromised, decline permission to board, noting that the vessel is proceeding in accordance with international law, as reflected in the Law of the Sea Convention.
Furthermore, if Iranian forces board a U.S.-flagged commercial vessel, the crew should not forcibly resist the boarding party. Refraining from forcible resistance does not imply consent or agreement to that boarding.
It is recommended that U.S.-flagged commercial vessels transiting these waters remain as far as possible from Iran’s territorial sea without compromising navigational safety. When transiting eastbound in the Strait of Hormuz, it is recommended that vessels transit close to Oman’s territorial sea.
- Industry transit advice for the Gulf of Oman, Strait of Hormuz, and Persian Gulf was issued on October 15, 2024, and can be found on the Maritime Global Security website.
- U.S.-flagged commercial vessels should coordinate voyage planning with U.S. Naval Forces Central Command (NAVCENT) Naval Cooperation and Guidance for Shipping (NCAGS) and consider their recommendations and guidance whenever possible.
- It is recommended that U.S.-flagged commercial vessels transit these waters with their Automatic Identification System (AIS) transponders on unless specifically advised otherwise by NAVCENT NCAGS. Some vessel seizures by Iranian forces were claimed to be a result of vessels not transmitting on AIS.
- American citizens abroad should inform the nearest U.S. embassy or consulate of their plans to transit the area and/or update their information via the Smart Traveler Enrollment Program (STEP).
- U.S.-flagged commercial vessels operating in these waters are advised to conduct a pre-voyage risk assessment, incorporate appropriate protective measures into vessel security plans, exercise caution, and monitor VHF Channel 16. In the event of any attack, incident, or suspicious activity, immediately activate the Ship Security Alert System, contact the U.S. Fifth Fleet Battle Watch, and contact the United Kingdom Maritime Trade Office (UKMTO).
- U.S.-flagged commercials vessels should register with the UKMTO 24 hours prior to entering the Indian Ocean Voluntary Reporting Area shown on UK Hydrographic Office Maritime Security Chart Q6099 utilizing the Initial Report and subsequent reports at UKMTO reporting formats.
- Include estimated times of arrival at the Strait of Hormuz (SoH), Bab el Mandeb Strait (BAM), and/or Suez Canal in the “Destination and estimated time of arrival” field of the report and add additional comments as needed (e.g., speed restrictions or other constraints, anticipated time of entering/exiting the SoH Traffic Separation Scheme, an outline of the vessel’s navigation plan for operating in the Persian Gulf, etc.) in the same Destination field. These reports will automatically be forwarded to NAVCENT NCAGS.
- Vessels operating in this area are advised to include the NAVCENT NCAGS watch on all update and incident report emails.
- Answer all VHF calls from coalition navies. Vessels should be aware that U.S. and other coalition naval forces may conduct maritime awareness calls, queries, and approaches to ensure the safety of vessels transiting these listed waters.
- Due to the risks of piracy, kidnapping, hijacking, and robbery while operating within U.S. Coast Guard designated High-Risk Waters (HRW), U.S.-flagged commercial vessels are required to comply with the Guidelines for U.S. Vessels Operating in High-Risk Waters contained in U.S. Coast Guard Maritime Security Directive 104-6 (Rev 9) and comply with their Coast Guard approved Vessel Security Plan annex on counter piracy. U.S. vessel owners and operators needing access to MARSEC Directive 104–6 should immediately contact their local Coast Guard Captain of the Port or District Commander for a copy of Revision 9.
