Sea-based transportation of any merchandise or persons shipped entirely or even partly by water between U.S. points—either directly or indirectly via one or any number of foreign points—U.S. Federal Law requires that said items or persons must travel in U.S.-built, U.S.-crewed, U.S.-citizen owned vessels that are U.S.-documented by the Coast Guard for such maritime "cabotage" carriage. This transportation/trade restriction includes Puerto Rico under the Jones Act of 1920 (Merchant Marine Act of 1920). The Jones Act and various other United States laws that govern the domestic and domestic-foreign-domestic transportation of merchandise and passengers by water between two points in the United States, including Puerto Rico, have been extended to that island-territory since the initial years of United States' political relations. Currently, the only providers who ship from the United States to Puerto Rico are Crowley Maritime, TOTE Maritime, and Trailer Bridge.