Several major cruise lines have ships that sail to and through the Hawaiian islands, but only one cruise line's fleet -- NCL America -- consists of U.S.-flagged vessels that offer Hawaii-only cruises. Due to an archaic law, the Passenger Services Act of 1886, foreign-flagged ships cannot "transport" passengers between U.S. ports without calling at a "distant foreign port" during the voyage. If your goal is to visit multiple destinations in Hawaii during a week-long cruise, then your choice is limited to NCL America's U.S.-flagged ships. If you have more time, Norwegian Cruise Line's foreign-flagged ship does Hawaii cruises for ten days, and visits Fanning Island in the Republic of Kiribati, which satisfies the foreign port requirement but makes your cruise more expensive. Other options involve sailing from the mainland U.S. and Canada.