46 CFR 5.101 – Conduct of investigations
(a) Investigations may be initiated in any case in which it appears that there are reasonable grounds to believe that the holder of a credential or endorsement issued by the Coast Guard may have:
(1) Committed an act of incompetency, misconduct, or negligence while acting under the authority of a credential or endorsement;
(2) Violated or failed to comply with subtitle II of title 46, U.S.C., a regulation prescribed under this subtitle, or any other law or regulations intended to promote marine safety or to protect the navigable waters, while acting under the authority of a credential or endorsement;
(3) Been convicted of a dangerous drug law violation, or has been a user of, or addicted to the use of, a dangerous drug, so as to be subject to the provisions of 46 U.S.C. § 7704.
(b) In order to promote full disclosure and facilitate determinations as to the cause of marine casualties, no admission made by a person during an investigation under this part or part 4 of this title may be used against that person in a proceeding under this part, except for impeachment.