46 C.F.R. § 201.124
Subpoenas issued under this section may be served upon the person to whom directed in accordance with subpart D of this part. Any person upon whom a subpoena is served may within seven (7) days after service or at any time prior to the return date thereof, whichever is earlier, file a motion to quash or modify the subpoena with the officer who issued the subpoena for action by him, and serve a copy of such motion to quash upon the party requesting the subpoena. If the person to whom the motion to modify or quash the subpoena has been addressed or directed has not acted upon such a motion by the return date, such date shall be stayed pending his final action thereon. The Administration may at any time review, upon its own initiative, the ruling of the officer denying a motion to quash a subpoena. In such cases, the Administration may at any time order that the return date of a subpoena which it has elected to review be stayed pending Administration action thereon.
46 C.F.R. § 201.124