USA Banner

Official US Government Icon

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure Site Icon

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation
MSCI Advisory

2024-004-Southern Red Sea, Bab el Mandeb Strait, Gulf of Aden, Indian Ocean, Somali Basin, Arabian Sea, Gulf of Oman, Strait of Hormuz, and Persian Gulf -Threats to Commercial Vessels

Description

This advisory supersedes and cancels U.S. Maritime Advisory 2024-001, incorporates new advice to U.S.-flagged vessels to turn off their AIS transponders when transiting the Southern Red Sea, Bab el Mandeb Strait, and Gulf of Aden, highlights Houthi deceptive communications, provides information on the new Joint Maritime Information Center, and updates other threat info.

1. References: None.

2. Issue: Regional conflict, military activity, terrorist attacks, and piracy pose significant threats to commercial vessels operating in the above listed geographic areas as evidenced by recent Houthi terror attacks and Somali piracy activity. The U.S. government is continually assessing the maritime security situation in the region to safeguard freedom of navigation, ensure the free flow of commerce, and protect U.S. vessels, personnel, and interests. The recent standup of Operation Prosperity Guardian and EUNAVFOR Operation Aspides are examples of U.S. and international cooperative maritime security operations within this region. The following are currently deemed to be the most pressing threats to U.S.-flagged and U.S.-affiliated commercial vessels throughout this region.

a) Houthi Hostile Actions: Commercial vessels transiting the Southern Red Sea, Bab el Mandeb Strait, and Gulf of Aden continue to be at an elevated risk of terrorism and other hostile actions from the Houthis. Hostile actions include one-way Unmanned Aerial Vehicle (UAV) attacks; Unmanned Surface Vehicle (USV) attacks; ballistic and cruise missile attacks; small arms fire from small boats; explosive boat attacks; and illegal boardings, detentions, and/or seizures. There have been at least 47 separate Houthi attacks on commercial vessels and one Houthi seizure of a commercial vessel in these areas, affecting over 55 nations since November 19, 2023. Entities claiming to be Yemeni authorities have also attempted to divert commercial vessels operating in these regions from their course. These threats pose both direct and collateral risks to commercial vessels transiting in international shipping lanes, or otherwise operating in these areas.

- In the last month, one vessel was sunk by the Houthis in the Bab el Mandeb Strait and one vessel was struck by the Houthis in the Gulf of Aden, resulting in loss of life and forcing the crew to abandon the vessel. Both incidents resulted in the issuance of navigation warnings. Commercial vessels operating in these areas should be vigilant for hazards to navigation caused by vessels being struck by the Houthis and should be aware of all current navigation warnings.

- U.S.-flagged commercial vessels transiting the Southern Red Sea, Bab el Mandeb Strait, and Gulf of Aden with AIS transponders on are at increased risk of targeting by adversarial actors. U.S.-flagged commercial vessels operating in these areas are strongly advised to turn off their AIS transponders, unless vessel Masters believe that doing so would compromise the safety of the vessel. The International Convention for the Safety of Life at Sea (SOLAS), Chapter V, regulation 19.2.4 and IMO Resolution A.1106(29) permit vessel Masters to turn AIS off if they "believe that the continual operation of AIS might compromise the safety or security of their ship, or where security incidents are imminent." See also 33 CFR § 164.46(d)(2)(v). While vessels have been attacked by the Houthis while AIS transponders were on and while off, turning AIS off makes it more difficult to track and accurately target a vessel. Adherence to all flag state and international requirements and guidance regarding operation of AIS, and the safe navigation of the vessel, remains the responsibility of individual companies and vessel Masters.

- U.S.-flagged commercial vessels operating in these areas are advised to remain as far as possible from Yemen’s coastline without compromising navigational safety. Crewmembers should be especially vigilant when at anchor, operating in restricted maneuvering conditions, loitering, or proceeding at slow speeds.

- 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. NAVCENT NCAGS stands a 24-hour watch and has the latest information on the current maritime security threats and the operational environment in this region.

  • The route taken through these areas and the timing of the transit remain at the discretion of individual companies and vessel Masters. Planned routes, waypoints, and speeds should not be duplicated from prior voyages, when possible. Transiting these areas during hours of darkness may frustrate efforts to target vessels.
     
  • U.S.-flagged commercial vessels are advised to provide hourly positional email updates to the NAVCENT NCAGS detachment when transiting these areas.
     
  • Maritime operators are advised to alert their crews to the fact that all electronics signals from their vessels pose a risk to maritime operations and are strongly advised to secure WiFi routers while underway in these areas when feasible.

- A missile strike on a Marshall Islands-flagged commercial tanker in the Gulf of Aden on January 26, 2024 resulted in a significant onboard fire. U.S.-flagged commercial vessels carrying flammable, explosive, or otherwise hazardous cargoes are strongly advised to reconsider transit through these areas. However, if planning voyages through these areas, vessels should take all prudent safety precautions, including thoroughly preparing for emergency responses, and consider carriage of additional safety and damage control preparedness supplies and equipment.

- If hailed on VHF by the Houthis, or entities claiming to be Yemeni authorities, and instructed to divert from their course, U.S.-flagged commercial vessels should ignore the VHF call and continue their passage if safe to do so. U.S.-flagged commercial vessels that encounter this tactic are advised not to follow Houthi direction to divert course, as doing so may enhance the ability of the Houthis to accurately target vessels. U.S.-flagged commercial vessels are advised to update the NAVCENT NCAGS detachment when this occurs.

- If the Houthis seek to board a U.S.-flagged commercial vessel in these areas, 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.

- When combined with evasive maneuvering, vessels transiting these areas with armed security details onboard have successfully deterred boarding by individuals in approaching small craft. The decision whether to embark a contracted armed security detail and assessment of associated risks is the responsibility of individual companies and vessel Masters, who are responsible for establishing use of force guidance and pre-planned responses for vessels carrying contracted armed security details.

- If Houthis board a U.S.-flagged commercial vessel without a contracted armed security detail onboard, the crew should not forcibly resist the boarding party. Refraining from forcible resistance does not imply consent or agreement to that boarding.

- When operating in these waters, U.S.-flagged commercial vessels should always maintain a proper, vigilant lookout by employing all suitable means in the prevailing circumstances and conditions. This includes incorporating additional lookouts to ensure a comprehensive assessment of the situation. See 1972 COLREGS, Rule 5. If U.S.-flagged commercial vessels observe or hear a suspected UAV or missile or observe a small boat approaching with apparent hostile intent, crewmembers not needed for the safe navigation and operation of the vessel should be relocated to a safe space until the threat has passed. Additional precautions should be taken to ensure small boats are kept at a safe distance whenever possible.

- In addition to U.S. Maritime Alerts and this Advisory, interim industry transit advice for the Southern Red Sea and Gulf of Aden is being distributed by Combined Maritime Forces (CMF). CMF guidance messages are available on the Maritime Global Security website at maritimeglobalsecurity.org/geography/goa-etc/.

- A new Red Sea/Gulf of Aden Joint Maritime Information Center (JMIC), which is a collaborative effort between Combined Maritime Forces, the Singapore Navy’s Information Fusion Center, the Royal Netherlands Navy’s NCAGS, the U.S. Navy Fifth Fleet’s NCAGS, and others, is now providing Weekly Dashboard and incident specific Info Notes regarding threats and incidents in this region at https://www.ukmto.org/indian-ocean/partner-products.

b) Iranian Illegal Boarding/Detention/Seizure: Commercial vessels transiting the Persian Gulf, Strait of Hormuz, Gulf of Oman, and Arabian Sea are at risk of being illegally boarded and detained or seized by Iranian forces. Recent incidents include the April 2023 Iranian seizure of a Marshall Islands-flagged vessel in the Gulf of Oman, the May 2023 Iranian seizure of a Panama-flagged vessel in the Strait of Hormuz, and the January 2024 Iranian seizure of a Marshall Islands-flagged vessel in the Arabian Sea. Iranian forces attempted to seize one Marshall Islands-flagged vessel and one Bahamas-flagged vessel in the Gulf of Oman during July 2023, but were prevented from doing so by U.S. Naval Forces. Iranian forces have utilized small boats and helicopters during boarding operations and have attempted to force commercial vessels into Iranian territorial waters.

- 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.

- 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 vessels in the Persian Gulf 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 Persian Gulf, Strait of Hormuz, and Gulf of Oman was issued on November 9, 2023, and can be found on the Maritime Global Security website at maritimeglobalsecurity.org/geography/goa-etc/.

c) Piracy and Armed Robbery Against Ships: Recent cases of piracy pose a threat to commercial vessels operating in the Gulf of Aden, Arabian Sea, Somali Basin, and Indian Ocean. Since November 2023, there have been three boarding/hijacking incidents, representing the first such attacks against commercial shipping in the region since March 2017. Pirates may utilize captured fishing vessels as motherships to target vessels operating hundreds of miles from the coast of Somalia. In November 2023, one Liberian-flagged vessel was boarded in the Gulf of Aden; in December 2023, one Malta-flagged vessel was hijacked in the Arabian Sea; and in January 2024, one Liberia-flagged bulk carrier was boarded in the Indian Ocean. Specific case details are available on the Office of Naval Intelligence's weekly "Worldwide Threat to Shipping" product at https://www.oni.navy.mil/ONI-Reports/Shipping-Threat-Reports/Worldwide-Threat-to-Shipping/.

- The Best Management Practices to Deter Piracy and Enhance Maritime Security in the Red Sea, Gulf of Aden, Indian Ocean and Arabian Sea (BMP5), and Maritime Global Security website at: https://www.maritimeglobalsecurity.org should be consulted prior to operating in those geographic waters.

- Transit by yachts and privately owned sailing vessels through these waters is hazardous and may result in capture. The U.S. Government advises against all operation of yachts and pleasure craft in these areas.

- 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) at: https://step.state.gov/step/. Yachting guidance can be found at: https://on-shore.mschoa.org/reference-documents/advice-for-sailing-vessels.

d) UAVs: Outside of the Southern Red Sea, Bab el Mandeb Strait, and Gulf of Aden, UAV attacks also pose a threat to commercial vessels in the Persian Gulf, Strait of Hormuz, Gulf of Oman, and Arabian Sea. The most recent attacks were on a Malta-flagged vessel in the Arabian Sea in November 2023, and on a Liberian-flagged vessel in the Arabian Sea in December 2023.

- If U.S.-flagged commercial vessels observe or hear a suspected UAV, crewmembers not needed for the safe navigation and operation of the vessel should be relocated to a safe space on the vessel until the threat has passed.

e) Limpet Mines: Limpet mines have been used to damage commercial vessels on multiple occasions in recent years and are primarily a threat to commercial vessels in the Persian Gulf, Strait of Hormuz, and the Gulf of Oman. Limpet mines, or similar improvised explosive devices, can be attached to vessel hulls, above or below the waterline, via swimmers or small boats, while a vessel is berthed, at anchor, or underway.

- When operating in these waters, U.S.-flagged commercial vessels should maintain a close lookout and remain vigilant for suspicious activity to include the approach of swimmers or small boats. Close attention should be given to the vessel’s waterline, especially at slow speeds, at anchor, and when moored.

- If a mine has been, or was attempted to have been, attached to a vessel, crewmembers not needed for the safe navigation and operation of the vessel should be relocated to a safe space on the vessel until the threat has passed.

3. Additional Guidance: U.S.-flagged commercial vessels operating in these waters are advised to exercise caution, review security measures, and monitor VHF Channel 16. To afford best protection in the region, U.S.-flagged commercial vessels are also advised to:

- 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
     
  • Contact UKMTO

- Simultaneously register with both the United Kingdom Maritime Trade Office (UKMTO) and the International Maritime Security Construct (IMSC) watch 24 hours prior to entering the Indian Ocean Voluntary Reporting Area by sending UKMTO and IMSC, via a single e-mail, the Initial Report from Annex D of (BMP5). Include the estimated times of arrival at the Suez Canal, Bab el Mandeb Strait (BAM), and Strait of Hormuz (SoH) in line 10 of the report and add line 14 for comments as needed (e.g., speed restrictions or other constraints, anticipated time of entering/exiting the SoH Traffic Separation Scheme; an outline of the navigation plan for operating in the SoH and Persian Gulf, etc.). Utilize other reports included in Annex D of BMP5 as necessary.

- Vessels operating in this area are advised to include both NAVCENT NCAGS and the IMSC watch on all updates or incident report emails. By including both as addressees on each email, awareness will be enhanced without creating an additional reporting burden.

- Conduct a pre-voyage risk assessment and incorporate appropriate protective measures into vessel security plans.

- The Maritime Global Security website at https://www.maritimeglobalsecurity.org/ offers industry issued best practices and guidance to mariners by geographic region and provides contact and subscription information for regional maritime security reporting centers, particularly in high risk-areas.

- 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 8) and comply with their Coast Guard approved Vessel Security Plan annex on counter piracy. The U.S. Coast Guard Office of Commercial Vessel Compliance (CG-CVC) announced in the Federal Register in August 2021 the availability of Revision 8 to Maritime Security (MARSEC) Directive 104–6. U.S. vessel owners and operators who needed to act under previous versions of MARSEC Directive 104–6 should immediately contact their local Coast Guard Captain of the Port or District Commander for a copy of Revision 8.

- Per 33 CFR 101.305, report all suspicious activities, breaches of security, and transportation security incident events involving U.S. vessels or persons to the U.S. Coast Guard National Response Center. Additional U.S. Coast Guard port specific requirements may be found in Port Security Advisory 1-22 at https://www.dco.uscg.mil/Portals/9/DCO%20Documents/InternationalPortSecurity/Port%20Security%20Advisory/PSA%20%201-22%20Remove%20Cote%20d'Ivoire.pdf?ver=6DzYOEsWAJQVh7ld4c0ycQ%3d%3d.

4. Contact Information:

a) Fifth Fleet Battle Watch: cusnc.bwc@me.navy.mil or + 973-1785-3879.

b) NAVCENT NCAGS: +973-1785-0033 (Primary/Watch Desk), +973-3940-4523 (Alternate), or m-ba-navcent-ncags@us.navy.mil.

c) IMSC: m-ba-imsc-bwc@us.navy.mil or +973-1785-8412/8192/8193. IMSC organizational information is available at https://www.imscsentinel.com/.

d) UKMTO: watchkeepers@ukmto.org or +44 (0) 2392 222060. UKMTO advisories and warnings are available at https://www.ukmto.org/.

e) U.S. Coast Guard National Response Center: +1-800-424-8802.

f) USCG NAVCEN: www.navcen.uscg.gov/contact/gps-problem-report or +1-703-313-5900.

5. Cancellation of Prior Advisories: This message supersedes and cancels U.S. Maritime Advisory 2024-001 and will automatically expire on September 14, 2024.

For maritime industry questions about this Advisory, contact the Global Maritime Operational Threat Response Coordination Center at GMCC@uscg.mil. Supplemental information about U.S. Maritime Alerts and Advisories, including subscription details, may be found at: https://www.maritime.dot.gov/msci. Feedback provided by U.S. maritime industry stakeholders regarding the U.S. Maritime Advisory System has greatly supported the USG in pursuing continued enhancements to this system. Feedback to MARADSecurity@dot.gov is always welcome.

Status:
Active