OBS_VALUE: The Jones Act (46 USC § 55101-55102) states that merchandise being transported by water between U.S. points must travel in U.S.-built and U.S.-citizen owned vessels that are registered in the United States. U.S. Customs and Border Protection (Customs) may grant waivers to these requirements in the interest of national defence.  When Customs receives a request for the use of a foreign vessel in U.S. domestic trade they must seek MARAD advice regarding U.S.-flag vessel availability before making a decision by law (46 U.S.C. § 501).  No waiver is granted if a U.S. flag ship is located.