46 CFR § 4.03-1 - Marine casualty or accident.
Marine casualty or accident means -
(a) Any casualty or accident involving any vessel other than a public vessel that -
(1) Occurs upon the navigable waters of the United States, its territories or possessions;
(2) Involves any United States vessel wherever such casualty or accident occurs; or
(3) With respect to a foreign tank vessel operating in waters subject to the jurisdiction of the United States, including the Exclusive Economic Zone (EEZ), involves significant harm to the environment or material damage affecting the seaworthiness or efficiency of the vessel.
(b) The term “marine casualty or accident” applies to events caused by or involving a vessel and includes, but is not limited to, the following:
(1) Any fall overboard, injury, or loss of life of any person.
(2) Any occurrence involving a vessel that results in -
(ix) Reduction or loss of a vessel's electrical power, propulsion, or steering capabilities;
(x) Failures or occurrences, regardless of cause, which impair any aspect of a vessel's operation, components, or cargo;
(xi) Any other circumstance that might affect or impair a vessel's seaworthiness, efficiency, or fitness for service or route; or
(xii) Any incident involving significant harm to the environment.
(3) Any occurrences of injury or loss of life to any person while diving from a vessel and using underwater breathing apparatus.
(4) Any incident described in § 4.05-1(a).