(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.

During an investigation, the investigating officer may administer oaths, issue subpoenas in accordance with subpart F of this title, and require persons having knowledge of the subject matter of the investigation to answer questions.

During an investigation, the investigating officer may take appropriate action as follows:

(a) Issue complaint.

(b) Accept voluntary surrender of a credential or endorsement.

(c) Accept voluntary deposit of a credential or endorsement.

(d) Refer the case to others for further action. The investigating officer may refer the case to the Commandant or to an Officer in Charge, Marine Inspection, at any port for completion of administrative action if an adequate basis for action is found and the person under investigation and/or witnesses are not locally available.

(e) Give a written warning. The investigating officer may give a warning to any person holding a credential or endorsement. Refusal to accept the written warning will normally result in a withdrawal of the warning and the preferral of charges. An unrejected warning will become a part of the person's record.

(f) Close the case.

(a) When the investigating officer determines that an S&R proceeding is appropriate, he or she shall prepare and serve a complaint in accordance with 33 CFR part 20.

(b) When the investigating officer serves the complaint, he or she shall also advise the respondent—

(1) Of the nature of S&R proceedings and their possible results;

(2) Of the right to be represented at the hearing by another person, who may, but need not, be a lawyer;

(3) Of the right to obtain witnesses, records, and other evidence by subpoena; and

(4) That failure or refusal to answer the complaint or to appear at the time, date, and place specified for the hearing may result in a finding of default, which will constitute an admission of the facts alleged in the complaint and the waiver of his or her right to a hearing.