((a)) ** .—** A person that violates this part or a regulation or order of the Federal Maritime Commission issued under this part is liable to the United States Government for a civil penalty or, in addition to or in lieu of a civil penalty, is liable for the refund of a charge. Unless otherwise provided in this part, the amount of the penalty may not exceed $5,000 for each violation or, if the violation was willfully and knowingly committed, $25,000 for each violation. Each day of a continuing violation is a separate violation.

((b)) ** .—** The amount of a civil penalty or, in addition to or in lieu of a civil penalty, the refund of a charge, imposed on a common carrier under this section constitutes a lien on the vessels operated by the carrier. Any such vessel is subject to an action in rem to enforce the lien in the district court of the United States for the district in which it is found.