The updated edition of the IMRF’s MRO guidance document, published in June 2025, is the most comprehensive guidance available for planning and preparing for Mass Rescue Operations (MROs) in the maritime environment and supports the information included in the International Aeronautical and Maritime Search and Rescue (IAMSAR) Manual.

The International Maritime Organization (IMO) defines a mass rescue operation as ‘characterised by the need for immediate response to large numbers of persons in distress such that the capabilities normally available to the search and rescue authorities are inadequate’. These complex and large-scale incidents are rare, meaning most search and rescue (SAR) organisations have limited experience in responding to them – yet they can occur anywhere, at any time, and have severe consequences.

It should be noted that the cause of the operation and the number of individuals involved are not specified. What is crucial is that a mass rescue operation is sufficiently large and complex to exceed the normal capabilities of local SAR authorities. In other words, there exists a ‘capability gap’. This gap must be addressed if everyone is to be rescued.

The guidance is divided into five sections, with each section further divided into chapters that contain essential information on MROs, including where to start and the processes to put in place.

This structured approach allows users to progress from foundational concepts to advanced operational considerations in a logical and practical manner. By adhering to the sequence of sections and chapters, planners and responders can develop a comprehensive understanding of what is required before, during, and after a mass rescue event.

Preparing for MROs necessitates inclusive planning, clear role definitions, and joint training among all parties involved, not merely authorities. Risk assessments must be continuous, with planners identifying vulnerabilities and addressing deficiencies in personnel and equipment. Plans should remain adaptable and undergo regular reviews and tests.

Operational success relies on effective communication, coordination, and support for survivors. Public messaging must be handled carefully, as miscommunication can impede the overall response. Accounting for everyone involved is notoriously challenging and must be supported by well-designed systems. During rescue operations, immediate triage, survivor welfare, and clear information sharing are essential. At times, on-scene support can supplement or replace evacuation efforts. Safe landing sites should be pre-identified and adequately equipped, with close coordination between maritime and shoreside teams.

Some MROs, such as those in remote areas or involving irregular migration, pose unique legal and logistical challenges. These incidents often involve overcrowded or unseaworthy vessels and politically sensitive decisions regarding the landing of survivors. Regardless of status, all individuals must be rescued and treated safely and humanely, with adherence to legal obligations such as non-refoulement. These operations demand legal awareness, coordination, and careful crowd management.

Effective resource planning involves identifying both expected assets, such as ferries and harbour craft, and unpredictable ones, like passing vessels. Regional cooperation is essential for overcoming capability shortfalls. Pre-arranged funding is also crucial to prevent delays during operations.

Clear command and control structures are essential. Strategic planning is overseen by SAR leadership, while tactical and operational tasks are undertaken by designated coordinators. These include SAR mission coordinator, on-scene coordinator(s), and air operations coordinators, all of whom must be adequately trained and empowered to act decisively.

Surface units and aircraft must be chosen based on their roles and appropriateness for the task at hand. Helicopters, drones, and other aerial assets are invaluable but must be utilised in coordination to guarantee both safety and effectiveness.

Strong integration between sea and shore responders ensures efficient transfer and care of survivors. Communication systems and protocols must be pre-established and clearly understood. Messaging to the public and families must be managed through unified structures, and misinformation, particularly on social media, must be actively managed.

Learning from experience is essential. Honest reviews of both real incidents and exercises help identify areas for improvement. Lessons must be shared, accepted, and acted upon to drive real change. Training should be targeted and promote cooperation across agencies. Exercises should progress from small simulations to full-scale drills, always prioritising safety. After-Action Reports formalise findings and support the continuous refinement of plans and training. Workshops and shared learning opportunities, including those provided by international organisations such as the IMRF, help bring stakeholders together, raise awareness, and strengthen response capabilities.

Collectively, the guidance emphasises that effective MRO preparedness requires ongoing planning, training, testing, and learning, grounded in collaboration, flexibility, and a shared commitment to saving lives.

The complete MRO guidance and the MRO summary guidance can be downloaded from the IMRF website at no cost and are also available to purchase in print.