33 C.F.R. § 146.303
Notice and written report of casualties
The owner, operator, or person in charge of a vessel engaged in OCS activities shall ensure that the notice of casualty requirements of § 146.30 and the written report requirements of § 146.35 are complied with whenever a casualty involving the vessel occurs which results in:
(a) Death;
(b) Injury to 5 or more persons in a single incident; or
(c) Injury causing any person to be incapacitated for more than 72 hours.