This all started last year when NIL-America which had 3 ships sailing in the Hawaiian islands (now down to 1 ship) somehow managed to get their lobbyist to have a change proposed to the PVSA which currently states that a foreign flagged ship must that sails to an American port must make a stop at a foreign port along the way.
The proposed change basically reads " The Customs and Border Protection agency has proposed tightening up the US cabotage law to bar foreign-flagged ships from transporting passengers between US ports unless they stop in a foreign port for at least 48 hours and have foreign ports comprise at least half of the itinerary."
See
http://www.traveltrade.com/news_article.htm?id=925 for more info.
The new changes are an attempt to save the NCL-America cruise line which can't seem to make a go of it sailing with an all American crew and if if this proposal does take effect (which could come at any time now) and if instated as originally written would devastate the cruise industry as we know it today. The new proposal states that the ships must also spend at least 1/2 the time at a foreign port as the time spent in an American one. Meaning that a Hawaiian cruise which stops for 4 days in Hawaii must now spend 2 days in Ensenada. This would put an end to the Hawaiian cruises leaving from the US as who in their right minds would pay for a 14 day Hawaiian cruise only to have to get 2 days in Hawaii since there isn't enough time for 4 days or increases the total days to 16 only to have to spend it in a depressing place like Ensenada. (worth about 20 minutes of my time) or leave from Ensenada & bypassing Long Beach, Ca. altogether. Of course you would have to fly (their airport can't handle it) or drive to Ensenada to catch the ship.
Many other cruise ports would also be affected (if not eliminated). I suppose the Alaskan cruises would also have to stop at a Canadian port for 48 hours cutting their time spent in Alaska meaning a 10 day cruise from San Francisco to the inside passage which now stops for 3 days would be cut to 2 days with 2 days at Victoria, BC.
There has been a lot of rumblings that the law would only be selectively applied to the Hawaiian market but nothing that could be confirmed. If my understanding of the proposed changes is wrong, please correct me. Either way it goes I doubt if I'd sail on NCL again in the future after what they've tried to do.