6Responsibility for investigating casualties and incidents

## 6 Responsibility for investigating casualties and incidents 6.1 Flag States are encouraged to ensure that investigations are carried out into all casualties occurring to its ships. All cases of serious and very serious casualties should be investigated. 6.2 Where a marine casualty or incident occurs within the territorial sea of a State, the flag and coastal States recognizing the obligations of that State to its citizens and the legal status of the territorial sea under the provisions of UNCLOS and also recognising the duties placed on a flag State, the flag and coastal States should co‑operate to the maximum extent possible, and mutually agree which State should take the role of lead investigating State. 6.3 Where a marine casualty or incident occurs on the high seas, a flag State should carry out an investigation into a casualty to, or on, any of its ships. If that casualty is a collision involving a ship of another flag State, then the States should consult with each other and agree which will be the lead investigating State and determine the best means of co-operation under this Code. In line with 9.1, if another State is a substantially interested State by virtue of the nationality of the ship's crew, passengers or other persons, or the location of the casualty, that State or States should be invited to take part in the investigation. 6.4 By fully participating in an investigation conducted by another substantially interested State, the flag State shall be considered as fulfilling its obligations under UNCLOS article 94, section 7. 6.5 An investigation should be started as soon as practicable after the casualty occurs. Substantially interested States should, by mutual agreement, be allowed to join an investigation conducted by another substantially interested State at any stage of the investigation.