There is a lot of competition in the cruise industry. The most competition is between Royal Caribbean International and Carnival Cruise Lines. Thy have been competing ever since they came into existence. They also have another competitor NCL(see Norwegian Cruise Lines for more info), but the two are more focussed on each other. RCI currently holds the title for the worlds largest ship, but Carnival holds the titles of the most popular cruise line and most successful. Who knows how long their competition will go on? It probably won't ever stop. But who knows????