A well known cruise line has extended its “Free Upgrades For All” special for several more days.

Originally advertised as ending on March 27, Norwegian Cruise Line  has extended the special until March 31, 2011.

Examples of the upgrades include a balcony cabin at the price for an oceanview cabin on select European and Mediterranean cruises from April 2011 through April 2013. A balcony cabin at the price for an oceanview cabin on select Caribbean cruises, round trip from Tampa, from November 2012 through April 2013. And a balcony cabin at the price for an oceanview cabin on select Bahamas cruises, round trip from Miami, from September 2011 through December 2011.

They are also offering a mini-suite for the price of a balcony cabin on select European and Mediterranean cruises from April 2011 through April 2013.

The special also includes a coupon book for $400 worth of spa treatments, time on the internet, photos and meals at onboard restaurants.

Norwegian Cruise Line has announced that as of April 1, 2011, the fares on all its ships, fleetwide, will go up 10%. So March 31 will not just be the end of the “Free Upgrades For All”, but will also be that last day that fares will be at the current rate.