46 U.S.C. § 7705: Subpenas and oaths

(a) An official designated to investigate or preside at a hearing on matters that are grounds for suspension or revocation of licenses, certificates of registry, and merchant mariners’ documents may administer oaths and issue subpenas to compel the attendance and testimony of witnesses and the production of records or other evidence during investigations and at hearings. (b) The jurisdictional limits of a subpena issued under this section are the same as, and are enforceable in the same manner as, subpenas issued under chapter 63 of this title.