Updated threats to shipping in the Red Sea


Published: 12 December 2023 Updated:

Credit to: Antony Velikagathu / Shutterstock.com

Update 27 February 2024

In recent weeks, the security landscape in the region has witnessed a significant upsurge in threats, characterized by their complexity and expanding reach. Reports have emerged suggesting that the Houthis have employed an "underwater drone" to target civilian ships, signalling a concerning new capability. However, due to the limited information available, it remains challenging to assess the true nature and effectiveness of this system.

One possibility under consideration is that the Houthis have successfully deployed a semi-submersible guided Improvised Explosive Device (IED), resembling a torpedo, which has been rumored since last December. The potential damage resulting from such an attack remains uncertain, given the various factors and unknowns involved in such a scenario. Coalition forces, supported by a range of surveillance and reconnaissance assets in the area, generally possess the capability to detect and mitigate such threats. However, it is important to acknowledge that this capability may not be foolproof in every situation.

Since the beginning of the Houthi campaign, vessels directly owned by Israeli companies have faced a severe level of threat, leading to a significant decrease in their transit through the Red Sea. Consequently, the Houthis have expanded their target selection to include vessels engaged in trade with Israel. Furthermore, there have been instances where attacks were likely based on outdated information from publicly accessible databases, highlighting the potential for unintended collateral damage.

The involvement of the United States and the United Kingdom in military operations has further widened the scope of potential Houthi targets. Notably, threats against these countries have received widespread attention, intensifying the risk level for vessels directly associated with both nations. This heightened risk extends to the four other countries actively supporting military strikes under Operation Poseidon Archer. Recent weeks have witnessed both attempted and successful attacks against merchant ships closely linked to the United States and the United Kingdom, demonstrating the Houthis' ongoing capabilities and their willingness to strike. These incidents have underscored that attacks are not confined solely to the southern Red Sea, as vessels have been targeted and struck in the Gulf of Aden.

Given the rapidly evolving nature of the situation, it is of utmost importance for all stakeholders to remain vigilant and closely monitor developments in the region. Risk Intelligence strongly advises implementing appropriate risk mitigation strategies to safeguard the safety and security of vessels and maritime operations.

In conclusion, the increasing threats, their complex nature, and expanding operational area require ongoing vigilance and proactive measures to protect vessels and maritime operations in the region. It is crucial for all stakeholders to closely monitor the situation and implement necessary risk mitigation strategies to ensure safety and security.

Update 15 February 2024

European Union member states are preparing to launch a naval mission in the Red Sea with the objective of safeguarding ships from attacks orchestrated by Yemen's Houthi militants. The leading role in this European naval mission, known as Operation Aspides, is expected to be assumed by Italy, focusing solely on defensive operations. The formal approval of the mission by the EU is anticipated on 19 February.

The maritime unrest in the Houthi-controlled areas of Yemen has made it a hotspot for attacks on ships perceived to have connections with Israel. In response, the initial phase of the operation will involve three vessels under EU command. France and Italy already have warships deployed in the region, and Germany plans to contribute the Hesse frigate to the mission.

Given the intricate geopolitical dynamics involving multiple stakeholders, the EU must be cautious not to inadvertently escalate tensions in the region. Meticulous planning and diplomatic finesse are essential in navigating the turbulent waters of the Red Sea.

It is crucial to acknowledge the ongoing threat of unmanned aerial vehicles (UAVs) in the Red Sea. In this regard, reference should be made to the OCIMF publication titled "Loitering Munitions – the Threat to Merchant Ships."

Update 5 February 2024

At the time of writing, there has been a significant decline, approximately 50%, in maritime traffic in the southern Red Sea and Bab el Mandeb area between November and late January. Notably, there has been a slight increase in the number of ships passing through Bab el Mandeb without broadcasting an AIS signal. Only around 10% of merchant ships passing through Bab el Mandeb have turned off their AIS.

Naval forces have recommended turning off the AIS signal, but there is currently no evidence to support the effectiveness of this measure in mitigating risks. Some ships have been targeted despite having their AIS turned off, suggesting that the Houthis have alternative methods of identifying and tracking their targets.

Container lines made the decision in mid-December to redirect their ships on routes between Europe and Asia. The remaining container ships passing through Bab el Mandeb are mostly smaller vessels engaged in regional feeder services. However, other segments of the shipping industry have experienced a more gradual decline in traffic.

According to Risk Intelligence's latest assessment, the ongoing military strikes carried out by US and UK forces, with support from four other countries, against Houthi forces in Yemen, may not effectively deter future Houthi attacks on commercial shipping. While it is possible that the ability of the Houthis to launch missiles may be diminished over time, it will be difficult to determine if this threat has been completely eliminated.

Risk Intelligence believes that the Houthi forces will still possess the capability to launch drone attacks, which require less land-based equipment. In addition to their existing stock of drones, the Houthis have demonstrated the ability to domestically produce drones using commercial components. Therefore, it is likely that the Houthis will continue their campaign in the coming weeks, although there are now fewer potential targets that meet their criteria. Since the seizure of the GALAXY LEADER in November, Houthi attacks have been targeted rather than indiscriminate, although some may have been based on misidentification due to outdated information in publicly available databases.

Updates in Alerts

  • The International Bargaining Forum (IBF) has included the Red Sea in its high risk area for crew contracts as of 22 December 2023 under the ITF Warlike and risk areas section (NB: the boundaries of the IBF high risk and warlike areas are different from the JWC listed areas.)
  • Industry associations (BIMCO, CLIA, ICS, IMCA, INTERCARGO, INTERTANKO and OCIMF) have revised the security guidance applicable to navigating in the Southern Red Sea and Gulf of Aden following a series of attacks by the Houthis. The guidance emphasises the importance of conducting a thorough ship and voyage-specific threat and risk assessment considering any additional advice from the ship's flag state before passing through the area in question. The guidance highlights that the maritime threat from the Houthi forces is greater in the vicinity of the Yemeni Red Sea coastline and also advises against following Houthi instructions to divert to Houthi-controlled ports for detention of the ship and crew and gives direction regarding suitable waiting areas in case of decision to postpone transit through the Southern Red Sea and the Gulf of Aden.
  • The following Flag States have published security circulars for their vessels when transiting the Red Sea region:
    o Panama,
    o Liberia,
    o Marshall Islands and
    o Norway
  • The United States Maritime Administration (MARAD) has cancelled the MSCI Alert 2024-001B - "Red Sea and Gulf of Aden – Potential Retaliatory Attacks by Houthi Forces" on 30 January.
  • However, the MARAD MSCI Advisory 2023-011 - "Persian Gulf, Strait of Hormuz, Gulf of Oman, Arabian Sea, Gulf of Aden, Bab al Mandeb Strait, Red Sea, and Somali Basin-Threats to Commercial Vessels" remains active.
  • On 26 January, INTERTANKO issued an update to its members stating that the threat level to ships with Israeli, UK and US interests remains high. However, targeting of vessels remains fluid and only the Houthis know who is being targeted and that its members should follow the advice contained in BMP5 and consider their policy related to keeping the AIS transmissions on during transits.

Update 26 January 2024

In response to a series of attacks and attempted attacks on civilian and naval vessels in the southern Red Sea and the Gulf of Aden since November, military forces from the United States and the United Kingdom, with support from Australia, Bahrain, Canada, and the Netherlands, initiated strikes against targets in Yemen. These strikes took place during the night of 11 January to 12 January, according to local time.

Subsequent strikes have been carried out as part of Operation Poseidon Archer. It is important to note that Operation Poseidon Archer is distinct from the US-led Operation Prosperity Guardian, which focuses on preventing and defending against future attacks on commercial shipping.

In addition, the EU member states have reached a political agreement in principle on 23 January, on the launch of a military operation to secure merchant shipping in the Red Sea. This was announced by the EU High Representative for Foreign Affairs after a meeting of foreign ministers in Brussels. According to diplomats, the mission should ideally commence next month.

On 24 January, the United States Maritime Administration (MARAD) issued the MSCI Alert 2024-001B-Red Sea and Gulf of Aden-Potential Retaliatory Attacks by Houthi Forces, which states the following:

"There continues to be a high degree of risk to commercial vessels transiting the Southern Red Sea between 12N and 16N. While the decision to transit remains at the discretion of individual vessels and companies, it is recommended that U.S. flag and U.S. owned commercial vessels remain North of 18N in the Red Sea or East of 46E in the Gulf of Aden until further notice. Additional updates will be provided when available. This alert will not automatically expire and will be updated or cancelled as needed. Any questions regarding this alert should be directed to U.S. Naval Forces NCAGS at +973-1785-0033 (Primary/Watch Desk), +973-3940-4523 (Alternate), m-ba-navcent-ncags@us.navy.mil (Contingency), or +973-1785-3879 (NAVCENT Battle Watch/Emergency)."

INTERTANKO published an update on 19 January, which advised that there are ongoing attacks against ships following the US and UK led strikes on Houthi missile sites in Yemen, which in turn has led to increased targeting of ships with US or UK interests. It should also be noted that ships with both active and inactive Automatic Identification System (AIS) have been targeted. The latest as issued by most flags now is that the Southern Red Sea and Gulf of Aden are now classified as ISPS Code level 3. INTERTANKO has further advised for shipowners and operators to continue to follow the guidance of BMP5, flag authorities, and military authorities in the area. As the situation remains volatile, it remains ambiguous that a ship will not be a target due to the uncertainties in targeting both through perceived links or by accident.

Shipowners should also consider their AIS transmission policies, with the US-led naval forces recommending ships to turn the AIS off in order to prevent the Houthis from identifying ship locations. However, the UKMTO has stated if a ship is passing through the area without AIS on, then this may delay them in their ability to send "see-and-avoid notices" directly to a ship.

Therefore, if the decision is taken to turn off AIS, then ships should instead increase the frequency of position reports to the UKMTO.

Update 17 January 2024

The joint military actions carried out by the United States and the United Kingdom have resulted in an expansion of potential Houthi targets in Yemen. Consequently, vessels associated with the US and UK, as well as the four other countries directly supporting the military strikes, face a significant level of threat.

Recent incidents in the Gulf of Aden have demonstrated that the Houthi forces still possess the capability to attack merchant ships. There have been both attempted and successful attacks on US-owned vessels, indicating the ongoing danger. It is worth noting that these attacks are not limited to the southern Red Sea, where the Houthis control a substantial portion of the Yemeni coastline and where another vessel was targeted in this area on 16 January.

The latest update from Risk Intelligence reported that while merchant ships linked to other countries participating in or supporting Operation Prosperity Guardian, as well as all other commercial vessels, face a lower level of threat, it is still considered elevated. For vessels associated with countries involved in Operation Prosperity Guardian, the primary concern lies in the potential for kinetic attacks, as the Houthi forces might focus on alternative targets. However, given their careful selection of targets, which aligns with their broader political objectives, such attacks are currently deemed unlikely.

For vessels not connected to countries participating in Operation Prosperity Guardian, Risk Intelligence assessed that the lower threat level primarily stems from the possibility of collateral damage. This could occur due to misidentification, proximity to kinetic attacks, or being in close proximity to drone and missile interceptions by military forces.

In the most recent development regarding security in the region, it has been reported that European Union member states have provided preliminary support for a naval undertaking aimed at safeguarding ships traversing the Red Sea. Notably, France, Italy, and Germany have taken the lead in committing to contribute to this mission. Nevertheless, there remains a vital requirement to establish precise rules of engagement that extend beyond mere patrolling, as well as to ensure its integration with other EU operations conducted off the coast of Somalia and in the Strait of Hormuz. Furthermore, a critical aspect to address is whether the mission will be authorised to board suspicious vessels in the event of weapons smuggling intended for the Houthi rebels.

Yemen port situation update

At the time of writing, commercial activity at seaports in Yemen, including Aden, Rudhum Oil Terminal, Mukalla, Ash Shihr Oil Terminal, Nishtun, Mokha, Saleef, Hudaydah, and Ras Isa Petroleum Products Reception Facility are at a restricted working level due to the security situation and the coalition’s naval operations. The ports of Ras Isa Marine Terminal and Balhaf LNG Terminal remain closed.

All vessels attempting to enter Yemeni waters must obtain permissions from coalition forces and the Hadi government, as well as to expect delays and multiple inspections, which can hold up vessels for weeks at a time. It is therefore recommended that port calls should be assessed on a case-by-case basis and updates to be obtained from Skuld’s local correspondent accordingly.

Current Yemen port entry conditions:

  • Owners and/or managers of merchant ships engaged in the transportation of commercial goods or services, including bilateral assistance that is not channelled through a UN agency or recognized international humanitarian organization, to ports not under the direct control of the Yemeni government are required to obtain prior clearance from the UN Verification and Inspection Mechanism for Yemen (UNVIM).
  • Requests for clearance should be submitted no later than five days before the vessel's arrival at the outer limits of these ports, preferably before the vessel's departure from its loading port, depending on the availability of the vessel's documents.
  • Please note that any clearance requests received after this deadline will result in delays in the clearance process. For more detailed information, including the UNVIM standard operating procedures, the list of required documents, and the clearance request form, please visit the UNVIM website.
  • Vessels intending to dock at ports controlled by the Yemeni government must continue to seek entry permissions through the Yemeni Ministry of Transportation. The completed entry permission form should be filled out and sent via email to the Operations Unit of the Supreme Relief Committee at yemen.transport@gmail.com at least one week before the vessel's intended entry/arrival.
  • Permission to enter Yemeni territorial waters will be granted only after an inspection carried out by the naval forces of the Saudi Arabian-led coalition.
  • Upon reaching the outskirts of Bab-el-Mandeb, approximately 3 nautical miles from Yemen's territorial waters, the vessel's Master must make a notice of arrival on VHF channel 16.
  • The naval forces of the Saudi Arabian-led coalition will then provide instructions on where the vessel should anchor while awaiting completion of the inspection and approval for port entry.
  • Once the vessel has been granted permission to enter the port, the Master must register the vessel's arrival with the port authorities (via VHF Channel 14 or 16), and the vessel will be assigned an anchoring position until the berthing time is confirmed by the Harbour Master.

Update 15 January 2024

The U.S. Central Command (CENTCOM) and BIMCO released further advises today that the security situation in the Red Sea area of 16N and 12N remains unstable.

The situation remains unpredictable and BIMCO further expects that the "present security conditions may prevail for still some time".

In particular, following the recent airstrikes in the Southern Red Sea from both sides – U.S. forces and the Houthis – over the weekend, with the most recent anti-ship cruise missile attack by the Houthis towards the USS Laboon on 14 January at 4:45pm (Sanaa time).

As such, the Combined Maritime Forces (CMF) and BIMCO continue to recommend shipping companies to consider avoiding operations in the area and to reposition to north of 18N or east of 46E.

The UKMTO currently advise vessels transiting the area to exercise caution and follow flag state and industry guidance.

Update 12 January 2024

In response to a series of recent attacks and attempted attacks on civilian and naval vessels in the southern Red Sea and the Gulf of Aden, a coalition of military forces led by the US, along with the United Kingdom and supported by Australia, Bahrain, Canada, and the Netherlands, carried out strikes on targets in areas of Yemen controlled by the Houthi forces.

These strikes mark a significant escalation in the ongoing Operation Prosperity Guardian, which began in December with the objective of deterring and defending against further attacks on commercial shipping. The decision to conduct these strikes followed a joint statement on 3 January 2024, which was widely perceived as a final ultimatum to the Houthi forces. In addition to the original coalition, the statement included the participation of eight additional countries: Belgium, Denmark, Germany, Italy, Japan, New Zealand, Republic of Korea, and Singapore.

Given these developments, various industry bodies including BIMCO, the Combined Maritime Forces (CMF) and the U.S. Naval Forces Central Command (NAVCENT) have advised that Red Sea transits are currently "extremely high risk". Accordingly, alerts were issued today recommending that all merchant ships refrain from operating in the Red Sea – specifically the areas from 12 to 16 degrees North and West of 46 degrees East in the Southern Red Sea and Bab el-Mandeb Straits - for at least the next 48 to of 72 hours.

Having consulted further with Risk Intelligence, they advised that it is important to note that claims of indiscriminate attacks against merchant ships have been made by the US and other countries, but available evidence does not fully support this conclusion. Risk Intelligence's thorough analysis of all incidents since November 2023, taking into account the military strikes against the Houthi forces, leads them (Risk Intelligence) to conclude that the threat to merchant ships is based on specific targeting rather than indiscriminate attacks on civilian shipping. It is therefore highly likely that Houthi forces will continue to select individual targets rather than engage in indiscriminate attacks on merchant ships.

Vessel type Threat type Threat level
Vessels specifically linked to Israel through ownership, port calls, trade with and/or commercial relationship between Israeli companies and owners/operators [1] Kinetic attack (missile, aerial/waterborne drone), possibly seizure and detention SEVERE
Vessels linked to the United States, United Kingdom and other countries involved in direct military strikes against Houthi forces Kinetic attack (missile, aerial/waterborne drone), possibly seizure and detention SEVERE
Vessels linked to other countries participating or supporting Operation Prosperity Guardian Kinetic attack (missile, aerial/waterborne drone), possibly seizure and detention ELEVATED
Other merchant ships in transit through the Red Sea/Bab el Mandeb Kinetic attack due to misidentification, potential proximity to the above threats (collateral damage) ELEVATED

Footnote: [1] The term "kinetic" generally refers to missiles or other traditional types of weapon systems that physically engage targets, whereas non-kinetic tools can include cyber, electronic warfare and other means of attack.
Source: Risk Intelligence A/S (as of 12 JAN 11:00 CET)

Risk Intelligence further assessed that the threat level to vessels directly owned by Israeli companies has been assessed as severe throughout the Houthi campaign. However, these vessels have largely ceased transiting the Red Sea. As a result, Houthi forces have expanded their potential targets, sometimes justifying them with tenuous links to Israel. The current escalation has led to an increased range of potential targets for the Houthi forces, especially considering their recent threats against the United States.

Consequently, vessels associated with the US and UK, as well as the four other countries directly involved in military strikes, face a severe threat level. Although retaliatory attacks against merchant ships from these countries are the most convenient option for the Houthi forces, it is unlikely that they will refrain from targeting naval vessels, which have already been attacked.

For merchant ships affiliated with other countries participating in or supporting Operation Prosperity Guardian, as well as for all other commercial vessels, the threat level is assessed as lower but still elevated. In the case of vessels related to countries involved in Operation Prosperity Guardian, the main concern lies in the potential for kinetic attacks, given that they may be perceived as alternative targets by the Houthi forces. However, due to the Houthi forces' careful selection of targets, which aligns with their broader political goals, Risk Intelligence evaluated that such attacks are currently deemed unlikely.

For vessels unrelated to countries participating in Operation Prosperity Guardian, the increased risk stems from the possibility of collateral damage or misidentification in proximity to kinetic attacks.

Given the ongoing volatility in the Red Sea, it is advisable for shipowners, operators, and Masters to thoroughly evaluate the risks associated with each transit on an individual basis. Additionally, it is recommended to refer to the published "Interim Industry Transit Advice, Southern Red Sea, and Gulf of Aden – 19 December 2023". Among other information, the document includes considerations about routing and vessel hardening.

The Combined Maritime Forces (CMF) have also issued a guidance document on 23 December 2023 - highlights to these important guidance has been published in our earlier update dated 10 January 2024.

Reference may also be made to the earlier update (dated 22 December 2023) related to "Guidance on commercial operations" and recommended mitigation measures.

Update 10 January 2024


Please find the below useful guidance for shipowners and operators, as extracted from the recent CMF publication of 23 December 2023. In conjunction with the CMF guidance, reference should also be made to the Maritime Global Security website for any further industry advice.

On approach to the Southern Red Sea

Reporting measures and information flow

The UKMTO Voluntary Reporting Area (VRA) is identified on maritime security charts such as UKHO Q6099. Ships entering and operating within the VRA are encouraged to register with the UKMTO. Registration establishes direct contact between the reporting ship and UKMTO. UKMTO acts as the primary point of contact for merchant ships and their CSOs, providing liaison with military forces in the region. UKMTO administers the Voluntary Reporting Scheme, under which merchant ships are encouraged to send regular reports. These include:

  1. Initial report (upon entering the VRA).
  2. Daily reports (update on ship's position, course and speed). The frequency of these may be increased by ships in the SRS especially if AIS "dark".
  3. Final reports (upon departure from VRA or arrival in port).
  4. Reports of suspicious/irregular activity (when necessary).

UKMTO can communicate with ships and CSOs directly, to disseminate Warnings and Advisories of incidents within the region:

  1. Warnings: Simple messages describing that an incident has occurred in a Lat/Long and with a time. This is normally accompanied by direct UKMTO-to-ship telephone calls to all ships within a nominated radius of the incident to give ships the earliest possible alert.
  2. Advisories: This is the next tier of alerts to ships, normally of sightings/reports that are relevant within the region.

UKMTO offers regular information to ships on its website and in a weekly report summarising the previous week's activity. UKMTO is also able to offer Masters and CSOs the opportunity to conduct drills and exercises to support their passage planning in the region. Companies that are interested can contact UKMTO at +44(0)2392 222060 or watchkeepers@ukmto.org.

Consideration of day or night transit

Timings and navigation of SRS transit remain the vessel Master's responsibility. Based on analysis of Houthi activity, it appears that UAVs are generally active during daylight hours. Transiting through the area to the west of Al Hudaydah during the hours of darkness may reduce the threat from UAV attack or frustrate efforts to target MV with missile systems. Although the detection of waterborne improvised explosive devices (WBIED) at night is difficult, it is also difficult for the Houthis to effectively direct them towards moving targets without visually identifying them.

Use of AIS

Adherence to IMO AIS guidance / regulations remains the responsibility of the Ship Manger and Master. Ships with AIS switched on and off have been attacked. Switching off AIS makes it marginally more difficult to track or target a ship but may also hinder the ability of the military to provide support or direct contact.

Navigating in the Southern Red Sea

Actions in the event of an attack

If contacted on VHF by "Yemeni Navy" and instructed to alter course to Al Hudaydah or another location on the NW coast of Yemen:

  • a. Ignore the VHF call and continue on passage if safe to do so.
  • b. Call for coalition warship on VHF Channel 16, inform them of your location, situation, state your intentions and seek advice.
  • c. Contact UKMTO, own Company Security Officer and the U.S. Naval Forces Central Command maritime operations centre at +973 1785 3879.  

Update 8 January 2024

The situation remains dynamic, with the list of potential targets expanding - possible links to Israel include port calls by vessels, trade with Israel in general, or commercial relationships with Israeli companies. Although vessels directly owned by Israeli companies face a higher threat level, they are currently not transiting the Red Sea. As a result, Houthi forces have widened their scope of potential targets to include the aforementioned categories. However, it is important to note the increased risk of collateral damage, especially in the densely trafficked southern Red Sea. There have been instances where Houthi forces have unintentionally targeted other merchant ships, indicating a dynamic and evolving threat that requires close monitoring. One such incident was reported on 3 December 2023 involving the bulk carrier AOM SOPHIE II.

The Houthis possess significant targeting capabilities, and can identify previous links to Israel. Attempts to conceal these links may be detected by the Houthis, although the precise criteria they use remains unknown. It is anticipated that such attacks will persist, unless deterred by the US or through behind-the-scenes pressure on the Houthis.

Vessels in transit should be mindful of the possibility of encountering small armed craft in the Indian Ocean area, particularly in the Gulf of Aden. These crafts could include fishermen, traders, smugglers, militias, irregular military forces, or naval and coast guard patrol vessels from southern Yemen or northern Somalia. The boarding of the product tanker CENTRAL PARK in the Gulf of Aden on 26 November, is believed to be linked to Houthi actions against vessels connected to Israel.

There is an ongoing potential for pirate operations in the Somali Basin and the Gulf of Aden. The Maltese-flagged bulk carrier RUEN was reportedly boarded about 400 nautical miles off the coast on 14 December and is suspected to have been hijacked. The situation regarding this incident remains unresolved, and it is unclear whether it represents an isolated event or an increased threat to merchant vessels in transit.

Several naval forces, including the US Navy, the Royal Navy, and the French Navy, have responded swiftly to the increased attacks. The French Navy has redeployed a Multi-Mission Frigate to provide support in the area. In response to the surge in attacks and the suspension of transit through the Bab el Mandeb by several companies, Operation Prosperity Guardian was launched on 19 December.

The Combined Maritime Forces (CMF) Guidance for Shipping Navigating the Southern Red Sea (SRS) was published on 23 December, which mentions that Operation Prosperity Guardian has commenced and "is a presence and deterrence mission in support of the Freedom of Navigation, that will be conducted by an international Naval force under CMF, commanded by Combined Task Force 153".

The CMF publication goes on to mention that vessels transiting in the SRS "will note a significant increase in the number of coalition warships and aircraft operating in the area as part of this operation. A review of BMP5 and the extant MSTC guidance for southern Red Sea will be conducted with industry".

Update 22 December 2023

Guidance on commercial operations

Ship transits

Several shipping industry organisations have published the Interim Industry Transit Advice, Southern Red Sea, and Gulf of Aden – 19 December 2023 which should be referred to by shipowners, managers and operators with vessels scheduled to transit the Red Sea. Among other information, the document includes considerations about routing and vessel hardening.

Please also refer to the below guidance from Risk Intelligence:

Vessel registration and incident reporting

It is strongly recommended for all merchant ships transiting the Western Indian Ocean, the Somali Basin, the Gulf of Aden, Gulf of Oman and the Red Sea to register with UKMTO and the Maritime Security Centre - Horn of Africa (MSCHOA). Any incidents or suspicious activities should also be reported to UKMTO and MSCHOA.

Contact details UKMTO

Email: watchkeepers@ukmto.org
Phone: +44 2393 222060
Website: www.ukmto.org

Contact details MSCHOA

Email: postmaster@mschoa.org
Phone: +33 298 220 220 or +33 298 220 170
Website: www.mschoa.org

If a vessel is under attack, US naval forces in Bahrain are able to coordinate assistance.

Phone: +973 1785 3879

Vessel operators are also advised to contact the respective flag state for additional guidance or requirements regarding incident reporting procedures.

Mitigation measures

Risk Intelligence strongly recommends merchant ship operators to assess whether the respective vessel has been owned or managed by Israel-affiliated companies in the past. Such information may not have been updated in publicly available databases and could lead to misidentification of current commercial links with Israel.

Prior to voyages through the Red Sea and the Gulf of Aden, ship operators should conduct a thorough ship and voyage-specific threat and risk assessment in line with shipping industry best practices. In addition, the following measures should be considered:

  • Constant monitoring of the security situation, enabling vessels to avoid locations with recent or ongoing incidents.
  • Introduction/update of contingency plans on the company level to address the possibility of seafarers being injured, killed or kidnapped during a security incident. The plan should include contingency and emergency plans; appropriate drills should be completed.
  • Crew briefings and scenario drills based on a valid and relevant anti-attack plan to ensure that incidents are reported and alarm is raised without delay when required. Drills should include scenarios with major damage and casualties.
  • Enhancement of firefighting, evacuation and damage control procedures, taking into account the possibility of significant damage as a result of direct targeting or collateral damage.
  • Enhancement of medical equipment to deal with multiple casualties.
  • Emergency contacts placed readily available on the bridge.
  • Bridge team briefing regarding hailing/harassment via VHF, prepared responses and immediate contact with naval forces in the respective area. (Local authorities' calls on VHF may be an act of spoofing or even targeting, underlined by several incidents in recent days which involved self-proclaimed 'Yemeni authorities' or the 'Yemeni navy' ordering merchant ships to alter course.)
  • Preparation of citadel with emergency provisions and functioning satellite phone.

In general, existing BMP5 recommendations have been developed to deter piracy. While the guidance included in BMP5 is relevant to deter illegal boardings, it offers virtually no mitigation against current threats such as attacks by missiles, drones or – potentially – waterborne IEDs ('drone boats').

Ship operators should also consider to issue specific voyage guidance for transits through the Red Sea and/or the Gulf of Aden. This guidance should consider specific scenarios (e.g. aerial or waterborne threats, hailing on VHF) and include actions for the crew to minimise the impact of any security incident.

Update 20 December 2023

Following the recent incidents in the southern Red Sea and the Gulf of Aden related primarily to Houthi forces, there is now a significant threat to merchant ships linked to Israel through a variety of commercial relationships. Although threats will vary on a case-by-case basis, the overall threat level for these vessels is now assessed as high.

The situation is evolving as the list of possible targets is expanding. Links to Israel may now be port calls by the respective vessel, owners/operators conducting trade with Israel in general or owners/operators being in commercial relationships with Israeli companies. To mitigate risks, it is recommended that Members evaluate whether their vessel was owned or managed by an Israel-affiliated company in the past year.

While the threat level to vessels which are directly owned by Israeli companies is assessed as even higher, it should be noted that virtually no such vessels are currently transiting the Red Sea. Houthi forces have, therefore, significantly expanded their potential targets, including the categories mentioned above.

At the same time, it is important to highlight the increased threat of collateral damage, particularly in the southern Red Sea with dense maritime traffic. It is very likely that Houthi forces have missed their intended targets on several occasions in recent days, increasing the potential for unintended strikes against other merchant ships. Although there has been an increase in military presence in the Red Sea, the distribution of this presence has been uneven despite successful interceptions of missiles and unmanned aerial vehicles (UAVs). Moreover, this is a highly dynamic and evolving threat which must be monitored closely in light of ongoing incidents.

Vessel type Threat type Threat level
Vessels specifically linked to Israel through ownership Seizure and detention; limited kinetic attack such as a drone strike SEVERE
Vessels linked to Israel through port calls, trade with Israel by owners/operators or commercial relationships between Israeli companies and owners/operators Seizure and detention; kinetic attack (missile, aerial/waterborne drone) HIGH
Vessels in transit without any involvement in Israeli trading Kinetic attack due to misidentification, potential proximity to the above threats (collateral damage) ELEVATED

Source: Risk Intelligence A/S (as of 18 DEC 18:00 UTC)

The Joint War Committee (JWC) has issued an amendment to the Listed Area of the Indian Ocean, Gulf of Aden, and the Red Sea (refer to JWLA-32) on 18 December to widen the high-risk zone in the Red Sea to 18 degrees north from 15 degrees north previously. The JWC deems the Red Sea as a high risk after a surge in attacks on commercial ships and to "reflect the missile range".

JWLA-32 amendments to the Listed Area of Indian Ocean, Gulf of Aden and Red Sea reads as follows:


Indian Ocean, Gulf of Aden and Southern Red Sea
The waters are enclosed by the following boundaries:

a) on the northwest, by the Red Sea, south of Latitude 18°N
b) on the northeast, from the Yemen border at 16°38.5'N, 53°6.5'E to high seas point 14°55'N, 53°50'E
c) on the east, by a line from high seas point 14°55'N, 53°50'E to high seas point 10°48'N, 60°15'E, thence to high seas point 6°45'S, 48°45'E
d) and on the southwest, by the Somalia border at 1°40'S, 41°34'E, to high seas point 6°45'S, 48°45'E

excepting coastal waters of adjoining territories up to 12 nautical miles offshore unless otherwise provided.


Moreover, the initiation of Operation Prosperity Guardian by the United States has been declared with the objective of safeguarding trade vessels in the Red Sea. Representatives from the Pentagon have disclosed that this multinational maritime security initiative will involve the participation of various countries, including the United Kingdom, Bahrain, Canada, France, Italy, Netherlands, Norway, Seychelles, and Spain. Regrettably, there is presently a lack of specific information regarding the operational procedures and naval resources to be employed under Operation Prosperity Guardian.

Operational and security risks

Maritime Global Security website – security advice

Interim Transit Advice for the Southern Red Sea and Gulf of Aden - 19 December 2023

Best Management Practices: BMP5 

Legal implications

Attacks on shipping in the Red Sea: contractual implications – 6 December 2023


Update 12 December 2023

On 9 December 2023, Yemen's Houthi movement said that it will target all ships heading to Israel, regardless of their nationality and warned all international shipping companies against dealing with Israeli ports.

In recent weeks, the Houthis have attacked and seized several Israeli-linked ships in the Red Sea and its Bab al-Mandab Strait, a sea lane through which much of the world's oil is shipped.

It is expected that such attacks will continue, subject to any deterrent response from the US, whose warships might also have been targeted with drones, and pressure applied on the Houthis behind the scenes, either through Saudi Arabia or other intermediaries, or a deal involving Iran.

Interim transit advice for the southern Red Sea and Gulf of Aden was published by BIMCO, ICS and other bodies in November 2023 and remains in place. The advice notes the following:

  1. Threats from "airborne activities are probably greater during daylight hours where targets are more easily identified and attacked/boarded, but the challenge of visually detecting and classifying small contacts at night such as a water-borne improvised explosive devices (WBIED) remain" – hence, the exposure to the threat is greater in daylight hours however, an attack during the hours of darkness cannot be excluded.
  2. Ships planning a passage through the Southern Red Sea and the Gulf of Aden should conduct a thorough ship and voyage specific threat and risk assessment, considering any additional advice from their flag state.
  3. Houthi forces have laid mines to protect port entries for ports under their control, and on rare occasion, such mines have become detached from their tether and have drifted into the traffic lanes.

There is also some potential for collateral damage due to vessels being in proximity to a missile/drone attack against another target or due to mistaken targeting.

Risk Intelligence released a client briefing report on 8 December addressing the viable threats to shipping, which reads as follows:

The seizure by the Houthis has achieved significant attention and highlights their opposition to Israeli actions in Gaza. The possibility of future vessel seizures hinges on several factors:

  • Whether the Houthis obtain any concessions through negotiations, potentially involving relevant parties from the Middle Eastern region.
  • The Houthis' ability to effectively manage the seized vessel, including the well-being and repatriation of the crew, as well as ensuring its security in Hudaydah.
  • Potential responses from Israel or an increase in the presence of naval forces in the area.
  • Behind-the-scenes pressure exerted on the Houthis through intermediaries or potential agreements with certain Middle East states.

It is therefore difficult to predict how this situation will play out. Based on our current assessment of the situation, Risk Intelligence sees the following threat levels.

Vessel type Threat type Threat level
Vessels specifically linked to Israel through ownership Seizure and detention; limited kinetic attack such as a drone strike HIGH
Vessels engaged in trading directly with Israeli ports Seizure and detention; protests and harassment ELEVATED
Vessels in transit without any involvement in Israeli trading Potential proximity to the above threats MODERATE


Given the ongoing volatility in Israel, it is advisable for shipowners, operators, and Masters engaged in trade with Israeli ports to thoroughly evaluate the risks associated with each port call on an individual basis. Additionally, the following measures are recommended:

  • Regularly consult local sources for up-to-date information from vessel agents, local authorities and Skuld's correspondent, to obtain the most current and reliable security information available.
  • Abide by the guidance provided by the flag administrations and port authorities regarding the relevant ISPS security levels.
  • Review and implement pertinent security and contingency plans as appropriate – enhance Best Management Practices.
  • Ensure that crewmembers aboard vessels heading towards Israel and transiting the Red Sea are well-briefed and trained about any imminent security threats in the region.
  • Ships with Private Maritime Security Teams onboard are advised not to escalate Rules for the Use of Force (RUF).

Israel is included in the Joint War Committee's (JWC) Listed Areas for Hull War, Piracy, Terrorism and Related Perils. As such it is also recommend confer with the vessel's war insurer in advance of arrival at any Israeli port or transit within the Red Sea.

Reference can be made to the Attacks on shipping in the Red Sea article published on 6 December, which answers some of the trade-related and contractual questions shipowners might have during this turbulent time.