Royal Caribbean has begun construction on its fifth Icon-class cruise ship, marking the milestone with a keel-laying ceremony held Monday at the Meyer Turku shipyard in Finland. The vessel is scheduled to enter service in 2028. The new ship will join a growing fleet of sister vessels built to the same design, including Icon of the Seas, Star of the Seas and Legend of the Seas, as well as Hero of the Seas, the fourth ship in the series, which was visible at the outfitting pier during the ceremony. Star of the Seas is currently based at Port Canaveral, Florida. The keel-laying event is a traditional shipbuilding milestone signifying the formal start of a vessel's construction, typically marked by the lowering of a large block section into the shipyard's dry dock. Meyer Turku, based in Turku, Finland, has served as the exclusive builder of Royal Caribbean's Icon-class ships, which rank among the largest passenger vessels in the world. Royal Caribbean has not yet released detailed specifications, a name or an itinerary for the fifth Icon-class ship. The company's fourth vessel in the class, Hero of the Seas, is currently undergoing final outfitting ahead of its own debut.