Harmony of the Seas, the upcoming world's largest cruise ship, has slid into the waters for the first time.

On Friday (June 19), the hulking shell of the vessel tested the waters off western France.

Since September 2013, Harmony of the Seas has been under construction in Saint-Nazaire shipyards. Nearly 2,500 workers have been involved in the building of the world's largest cruise ship.

The vessel is set to be ready for inaugural trip from Southampton to Barcelona in May 2016. It will measure 362 metres in length and will weight approximately 227,000 tonnes. The construction of the vessel will require 500,000 litres of paint and 90,000 square metres of carpet. Harmony of the Seas will be able to accommodate 6,360 guests and 2,100 crew members.