3. Oasis of the Seas – Royal Caribbean International
Launched in 2009, Oasis of the Seas was the first in the Oasis class to set a new standard for size in the cruise industry. It measures 1,186 feet in length and has a gross tonnage of 226,838, with a capacity to host 6,780 guests. Features include zip lines, aqua theaters, and ice skating rinks.
4. Allure of the Seas – Royal Caribbean International
Allure of the Seas is virtually identical to its sister, Oasis of the Seas, but is officially 2 inches longer, making it the second-largest cruise ship when it debuted in 2010. It shares many of the same amenities as its siblings, including themed neighborhoods and high-diving performances.