P.L. 66-261, also known as the Jones Act, provides for the promotion and maintenance of a U.S. merchant marine. Provisions dealing with cabotage (i.e., coastal shipping) require that all goods transported by water between U.S. ports be carried in U.S.-flag ships, constructed in the United States, owned by U.S. citizens, and crewed wholly by U.S. citizens. In addition, amendments to the Jones Act, known as the Cargo Preference Act, provide permanent legislation for the transportation of waterborne cargoes in U.S.-flag vessels.