46 U.S.C. § 55103: Transportation of passengers

(a) In General.—Except as otherwise provided in this chapter or chapter 121 of this title, a vessel may not transport passengers between ports or places in the United States to which the coastwise laws apply, either directly or via a foreign port, unless the vessel—(1) is wholly owned by citizens of the United States for purposes of engaging in the coastwise trade; and (2) has been issued a certificate of documentation with a coastwise endorsement under chapter 121 or is exempt from documentation but would otherwise be eligible for such a certificate and endorsement. (b) Penalty.—The penalty for violating subsection (a) is $300 for each passenger transported and landed.