Cruise Royal Caribbean orders fourth Oasis-class ship By Tom Stieghorst / May 11, 2014 Share 1 -- Royal Caribbean Cruises Ltd. said it will move forward with a fourth in its Oasis-class of ships, the largest in the world at 5,400 passengers and 225,000 gross tons. RCCL Chairman Richard Fain made the announcement at the STX France shipyard in St. Nazaire while there for the keel laying ceremony of the third Oasis-class ship, which is to be delivered in 2016. The first two ships in the class, the Oasis of the Seas and the Allure of the Seas, have been in high demand since they debuted in 2009 and 2010, respectively. They both sail Caribbean itineraries from Port Everglades. The fourth Oasis-class ship is scheduled to be delivered in 2018. RCCL hasn't announced where either ship will be sailing after delivery. Each of the ships costs more than $1 billion to build, but RCCL didn't disclose an exact price for the newly ordered vessel. Follow @tstravelweekly on Twitter.