Under SOLAS regulation I/21 and MARPOL articles 8 and 12, each Administration undertakes to conduct an investigation into any casualty occurring to ships under its flag subject to those conventions and to supply the Organization with pertinent information concerning the findings of such investigations. Article 23 of the Load Lines Convention also requires the investigation of casualties.

Under the United Nations Convention on the Law of the Sea (UNCLOS), article 94 on Duties of the flag State, paragraph 7, “Each State shall cause an inquiry to be held by or before a suitably qualified person or persons into every marine casualty or incident of navigation on the high seas involving a ship flying its flag and causing loss of life or serious injury to nationals of another State or serious damage to ships or installations of another State or to the marine environment. The flag State and the other State shall co-operate in the conduct of any inquiry held by that other State into any such marine casualty or incident of navigation.”

IMO adopted a new Code of International Standards and Recommended Practices for a Safety Investigation into a Marine Casualty or Marine Incident (Casualty Investigation Code) when the Maritime Safety Committee (MSC) met in London, for its 84th session in May 2008.

Relevant amendments to SOLAS Chapter XI-1 were also adopted, to make parts I and II of the Code mandatory. Part III of the Code contains related guidance and explanatory material.

The new regulations, entered into force on 1 January 2010 and expand on SOLAS regulation I/21, which only required Administrations to undertake to conduct an investigation of any casualty occurring to any of its ships "when it judges that such an investigation may assist in determining what changes in the present regulations might be desirable". The Code now requires a marine safety investigation to be conducted into every "very serious marine casualty", defined as a marine casualty involving the total loss of the ship or a death or severe damage to the environment.

The Code also recommends an investigation into other marine casualties and incidents, by the flag State of a ship involved, if it is considered likely that it would provide information that could be used to prevent future accidents.

The Organization has encouraged cooperation and recognition of mutual interest through a number of resolutions.  The first was resolution A.173(ES.IV) on Participation in Official Inquiries into Maritime Casualties adopted in November 1968. Other resolutions followed including: resolution A.322(IX) on Conduct of Investigations into Casualties adopted in November 1975; resolution A.440(XI) on Exchange of Information for Investigations into Marine Casualties and resolution A.442(XI) on Personnel and Material Resource Needs of Administrations for the Investigation of Casualties and the Contravention of Conventions, both adopted in November 1979; resolution A.637(16) on Co-operation in Maritime Casualty Investigations, adopted in 1989.

These individual resolutions were amalgamated and expanded by the Organization with the adoption of the Code for the Investigation of Marine Casualties and Incidents.  Resolution A.884(21) on Amendments to the Code for the Investigation of Marine Casualties and Incidents resolution A.849(20), adopted in November 1999, provided guidelines for the investigation of human factors. The Assembly, at its twenty-eighth session, adopted resolution A. 1075(28) on Guidelines to assist investigators in the implementation of the Casualty Investigation Code (resolution MSC.255(84)), revoking resolutions A.849(20) and A.884(21).

The Sub-Committee on Implementation of IMO Instruments (formerly the Sub-Committee on Flag State Implementation(FSI)) re-established the Correspondence and Working Groups on Casualty Analysis involved in all casualty-related matters and in the process of analysing reports of investigations into casualties received by the Secretariat. The recommendations of the Correspondence and Working Groups are approved by the III Sub-Committee and forwarded to other IMO bodies as appropriate.

The activity of the groups on casualty analysis is based on the Casualty analysis procedure which includes a process of analysis of casualty investigation reports, graphic representation of the typical flow of casualty information, procedures for evaluating safety issues that need further consideration, a graphic representation of the process to validate a safety issue and assignment of estimated risk level and a diagram of the casualty analysis process.

The Global Integrated Shipping Information System (GISIS) includes a Maritime Casualties and Incidents module database, which includes data on Maritime Casualties and Incidents (MCI), as defined by circulars MSC-MEPC.3/Circ.3/Rev.1.

This GISIS module also includes all casualty analyses which were approved by the FSI Sub-Committee for their release to the public on the GISIS module, where they can be accessed. GISIS also includes a Contact Point module where it is possible to search flag State contact points for PSC matters, Casualty investigation services and Ships' inspection services (including Secretariats of Memoranda of Understanding on Port State Control).

The MCI module contains information collected through MSC-MEPC.3/Circ.4/Rev.1, as well as full investigation reports uploaded into the system. Part of this information is accessible to IMO Members only.

Lessons Learned are approved by the III Sub-Committee and are circulated to seafarers in order to increase awareness of seafarers to accidents for prevention purposes.

Reporting to IMO of marine safety investigations and marine casualties and incidents are based on the following IMO instruments:

  • Code of International Standards and Recommended Practices for a Safety Investigation into a Marine Casualty or Marine Incident (Casualty Investigation Code), 2008 edition (resolution MSC.255(84)), paragraph 14.1, chapter 14 of the mandatory Part II;
  • Guidelines to assist investigators in the implementation of the Casualty Investigation Code (resolution MSC.255(84) (resolution A. 1075(28)); 
  • Safety of fishermen at sea, resolution A.646(16), paragraph 3;
  • Reports on casualty statistics concerning fishing vessels and fishermen at sea, MSC/Circ.539/Add.2, paragraph 2;
  • Report on fishing vessels and fishermen statistics, MSC/Circ.753, paragraph 3;
  • Provision of preliminary information on serious and very serious casualties by rescue co-ordination centres, MSC/Circ.802, paragraph 3;
  • Guidance on near-miss reporting, MSC-MEPC.7/Circ.7, paragraph 4; and
  • Casualty-related matters, Reports on marine casualties and incidents, MSC MEPC.3/Circ.4/Rev.1, paragraphs 6 and 8. 
  • The IMO Secretariat worked with the European Maritime Safety Agency (EMSA) for harmonizing reporting procedures with the European Marine Casualty Information Platform (EMCIP) and avoiding duplication of reporting.

    Applicable IMO instruments on casualty matters