How big is too big? Apparently that question has never been asked in cruise ship design. Next year, Royal Caribbean cruise line is scheduled to launch two Oasis Class ships, which would be the largest cruise ships ever.
So, how big is the Oasis class cruise ship? The first one, Oasis of the Seas, will be 118 feet (36 m) longer than the Eiffel Tower. It's so large that it has its own "Central Park" in the middle of the ship that is open to the sky and filled with lush tropical gardens, restaurants, and (of course) shops.
Links: Oasis of the Seas by Royal Caribbean | Wikipedia entry - via The Bad Rant
http://www.oceana.org/north-america/what-we-do/stop-cruise-ship-pollution/
http://www.cruiseshipstories.com