The purpose of safety investigations into marine accidents is to reduce the risk of future casualties and incidents and reduce their serious consequences including loss of life, loss of ships and pollution of the marine environment. Through application of common methodology and an objective and systemic approach to the investigation, the investigative body should best be able to draw lessons from each accident and so enhance maritime safety. Proper identification of the causes of a marine casualty or incident requires timely and methodical investigation, going beyond the immediate evidence and looking for underlying conditions which may cause other future occurrences. Investigation may therefore be seen as a means of identifying not only immediate causes, but also issues in the total environment from regulation and policy through to implementation.
海难调查是一种行政程序，本质上是补救性的。大多数海洋调查的职能涉及“事故”，可以将这类事件视作不希望发生或不需要政府出面干预的事件。相关事件可能直接涉及船舶事务，如扣留、伤亡、违反条款（MARPOL 73/78、TSS 和 Celeg）和漏油等。
Vessel casualty investigations cover a variety of incidents including, but not limited to; fire, explosion, collision, grounding, contact, heavy weather damage, hull cracking and defects.Casualty investigations also include looking into possible violations of law or failure on the part of personnel, shipowners, or ship operators, which could result in personnel action against licenses, certificates of competency or seafarer documents. Incidents may also be personnel related such as death or an injury, failure to properly perform duties, crew grievances, or an act of fraud or misconduct. An interaction between “incidents” is also possible such as a shipboard explosion that injures a seafarer or improper navigation that results in a vessel grounding or collision. Any incident may relate also to issues such as embargoes, treaties, tariffs, desertion, stowaway, crew wages issues, etc.
SOLAS Chapter 1, Regulation 21 requires Administrations to investigate certain casualties and to notify the IMO of the results. The Palau Registry Administration will investigate casualties occurring on Palau-flagged vessels when an investigation may assist in determining what changes may be useful to the amendment of the present rules and regulations.