The next Oasis-class cruise ship from Royal Caribbean will be named Harmony of the Seas. And it will feature the line’s first ever water slides!  The ship is set to debut in April 2016 and will feature three water slides that start from the top-deck Pool and Sports Zone and twist and turn down three decks into one of two pools.  A fourth Oasis-class ship (still-unnamed) will begin sailing in 2018. Meanwhile, the new Anthem of the Seas will debut this spring and will feature the North Star, a jewel-shaped glass capsule that rises 300 feet above sea level; RipCord by iFly, a skydiving simulator; and SeaPlex, the largest indoor sports and entertainment complex at sea, with everything from bumper cars and roller skating, to video gaming and a circus school complete with a flying trapeze.  The ship will be based in Southampton, England this summer offering Mediterranean itineraries before redeploying to Cape Liberty, New Jersey where it will sail seven- to 12-night Bahamas and Caribbean itineraries beginning November 2015.