The Republic of the Marshall Islands Maritime Administrator warns about threats to commercial vessels in four areas

The Republic of the Marshall Islands Maritime Administrator on 13 July 2023 issued a ship security advisory SSA-03-23 (Rev. 3) warning shipowners, operators, masters, company security officers, and recognized security organizations about threats to commercial vessels in four areas.

The Republic of the Marshall Islands (RMI) Maritime Administrator (the "Administrator") requests shipowners and operators to circulate this advisory expeditiously to their RMI-flagged vessels that are operating in or intend to operate in the Arabian/Persian Gulf, Strait of Hormuz (SoH), Gulf of Oman, or Arabian Sea.

Heightened military activity and geopolitical tensions in these regions continue to pose serious threats to commercial vessels. Vessels transiting these areas should maintain a heightened level of vigilance.

Recent Incidents

1.1 Two RMI-flagged vessels and a Bahamas-flagged vessel were recently harassed by foreign military vessels while transiting international waters as follows:

  • 4 June: An RMI-flagged bulk carrier operating off Mina Saqr, United Arab Emirates.
  • 5 July: An RMI-flagged tanker transiting the Gulf of Oman just north of Muscat, Oman.
  • 5 July: A Bahamas-flagged tanker was approached by the Iranian Navy. When that tanker refused to follow the Iranian Navy, shots were fired, striking the commercial tanker.

1.2 In all three incidents, naval forces from the International Maritime Security Construct (IMSC) were able to intervene and deter the attacks.

1.3 These incidents are in addition to the one involving the RMI-flagged crude oil tanker, ADVANTAGE SWEET, that was forcibly seized by the Iranian Navy in April 2023 while transiting international waters in the Gulf of Oman and is currently being held by Iranian authorities in Bandar Abbas.

Harassment, Boarding, Detention, and Seizure by Foreign Military Forces

2.1 Commercial vessels transiting through the Arabian/Persian Gulf, SoH, and Gulf of Oman have been boarded and detained or seized by foreign military forces over the past several years. They include the following seizures:

Credit: RMI Maritime Administrator

2.2 Local military forces have utilized small boats and/or helicopters during boarding operations and have attempted to force merchant vessels into their territorial waters.

Although some incidents may have targeted specific merchant vessels due to their association with certain countries, cargo, individuals, or companies, the potential remains for miscalculation or misidentification that could lead to aggressive actions against any merchant vessel.

Coalition Forces

3.1 A listing of naval coalition forces, their remits, and contact information is included in Appendix A (see below).

3.2 Vessels should be aware that the United States (US) and other coalition naval forces may conduct maritime awareness calls, queries, and approaches to ensure the safety of vessels transiting the Arabian/Persian Gulf, SoH, Gulf of Oman, and Arabian Sea.

If a vessel suspects it is being hailed from a source falsely claiming to be a US or coalition naval vessel, UK Maritime Trade Operations (UKMTO) and IMSC should be immediately informed.

3.3 Vessels operating in this area are advised to establish contact with both UKMTO and IMSC and to include both on all updates or incident report emails (see §6.0 on Voluntary Reporting Schemes and Appendix A for contact details).

By including both as addressees on each email, awareness will be enhanced without creating an additional reporting burden.

If the vessel also has links to a European-led Maritime Awareness in the Strait of Hormuz (EMASoH) member State (as listed in Appendix A), the EMASoH should also be included in all email communications.

Non-Coalition Forces

4.1 If hailed by non-coalition forces, provide vessel name, flag State, and affirm that the vessel is proceeding in accordance with international law as reflected in the United Nations Law of the Sea Convention (UNCLOS).

The Master should immediately inform UKMTO, IMSC, and EMASoH (if applicable).

Refer also to www.imscsentinel.com and IMSC Bridge Reference Cards for additional guidance and standard responses.

4.2 If non-coalition forces seek to board a vessel navigating these waters, the ship'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 UNCLOS, and immediately inform UKMTO, IMSC, and EMASoH (if applicable).

4.3 If non-coalition forces board a vessel, the vessel should immediately contact UKMTO, IMSC, and EMASoH (if applicable).

The crew should not forcibly resist the boarding party.

Refraining from forcible resistance does not imply consent or agreement to that boarding.

Risk Mitigation Measures

5.1 Vessels should take the following precautions when operating in the area:

  • Implement Ship Security Level 2 (flag requirement).
  • Review BMP5*.
  • Undertake a pre-voyage threat and risk assessment before entering any region where there has been an incident or if the threat has changed.
  • Review the Ship Security Plan and amend if necessary after performing the pre-voyage security threat and risk assessment.
  • Ensure Automatic Identification Systems (AIS) and Long-Range Identification and Tracking (LRIT) systems are switched on and functional.
  • Privately Contracted Armed Security Personnel (PCASP) should not be used as a risk mitigation measure in the northern Gulf of Oman, SoH, or Arabian/Persian Gulf.
  • Ensure voyage data recorder (VDR) data is preserved in the event of a boarding, attack, or suspicious event.
  • Conduct security training/drills/exercises prior to entering areas of increased risk.
  • Strictly observe any promulgated exclusion zones or guidance issued by coastal states.
  • Maintain a full and vigilant bridge watch for small craft approaching.
  • Monitor relevant very high frequency (VHF) and other communication channels. Answer all calls professionally. DO NOT IGNORE.
  • Vessels should follow the advice of coalition military authorities (UKMTO, Combined Maritime Forces (CMF), IMSC, and/or EMASoH).

*Best Management Practices to Deter Piracy and Enhance Maritime Security in the Red Sea, Gulf of Aden, Indian Ocean and Arabian Sea, 5th Edition (BMP5).

Voluntary Reporting Schemes

6.1 Vessels are reminded to:

  • Participate in all available and applicable voluntary reporting schemes to ensure communication is maintained directly with coalition forces in the region.
  • Simultaneously register with both UKMTO and IMSC 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, BAM, and SoH in line 10 of the report and add a 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.

6.2 Vessels with links to EMASoH member States (including beneficial ownership, ship management, International Safety Management (ISM) Company, Charterer, or cargo) should also participate in the EMASoH voluntary reporting scheme.

Reporting an Incident or Suspicious Activity

7.1 In the event of an incident or suspicious activity, contact UKMTO, IMSC, and EMASoH (if applicable), and activate the Ship Security Alert System (SSAS) immediately.

7.2 All security incidents must be reported to the Administrator at: marsec@register-iri.com, dutyofficer@register-iri.com, and +1 571 441 1885.

Supplemental Information

8.1 The Maritime Global Security website at www.maritimeglobalsecurity.com offers industry-issued best practices, including BMP5, guidance to mariners by geographic region, and provides contact and subscription information for regional maritime security reporting centers.

BMP5 and the Maritime Global Security website should be consulted prior to operating in the above listed geographic areas.

8.2 Refer to the RMI Maritime Security webpage.

Credit: RMI Maritime Administrator

This SSA is evaluated annually by the Administrator and expires one year after its issuance or renewal unless otherwise noted,
superseded, or revoked.


For more information, please see the document below (available only to subscribers):


Threats to Commercial Shipping: The Strait of Hormuz Region