The Railway and Maritime Investigations Office’s investigation activity is mandatory in the case of serious railway accidents or very serious maritime accidents. In addition, Office for Railway and Maritime Investigations may investigate serious or less serious or marine casualties and incidents which, under different conditions, could have led to very serious marine casualties, taking into account both the level of risk of the accidents/incidents/incidents themselves and the possible impact of the event investigated on maritime safety as a whole. It is, therefore, essential that the investigating body becomes aware, as soon as possible, of all accidents, incidents and accidents that are related to safety issues and that such information is provided by the various parties involved, according to criteria of homogeneity and reliability of the data, with respect to a defined typological classification of accidental events.