Royal Caribbean International has announced a 274-night, ... Royal Caribbean’s Ultimate World Cruise is being billed as the world’s longest cruise at 274 nights and including 65 countries.

Royal Caribbean's Serenade of the Seas ship will sail on what the line is calling the "longest and most comprehensive" world cruise to depart in 2023.

Royal Caribbean International and Celebrity Cruises are two of the most well-known, well-loved cruise brands, so you won't have a bad time on either line. Still, they cater to different types of ...