Symphony of the Seas under construction at the STX shipyard in France.

(1 p.m. EDT) -- Royal Caribbean's Symphony of the Seas, the line's fourth Oasis class ship, will debut earlier than planned, with its first sailing now departing three weeks ahead of schedule.

According to a Royal Caribbean statement, "The advanced timeline is a result of experience and efficiencies garnered with STX France, the same ship yard where Harmony of the Seas was built in 2016."

With its earlier launch date in place, Symphony of the Seas will now sail three additional voyages. The first, a pre-inaugural sailing departing March 31, 2018, will be a five-day cruise out of Barcelona with stops in Naples and Rome. Two seven-night cruises will depart on April 7 (the ship's official inaugural cruise) and 14, with stops in Palma De Mallorca, Marseille, Livorno, Civitavecchia and Naples.

Symphony of the Seas will be the world's largest cruise ship when it launches. It will introduce new-to-the-line cabin categories, restaurants and entertainment venues, as well as a re-imagined Boardwalk.

--By Dori Saltzman, Senior Editor