Originally Posted by skofarrell
Cruise ships have to stop at a foreign port before coming back to the US in order to satisfy both laws, otherwise they can't let anyone get off and stay off. Canada and the Carribean do count, Alaskan cruises that leave out of Seattle stop in BC to skirt both acts. Bahamas cruises out of FLA go to, well, the Bahamas.
Just to note, not every cruise ships have to stop at a foreign port before coming back to the US... NCL have some US Flagged ships sailing around Hawaii, nice ships too.