Due to debut in 2023, Icon of the Seas will be the line’s first vessel powered by liquified natural gas (LNG).
It will be the first of three Royal ships to use LNG, and will also utilise shore power to reduce carbon output.
Michael Bayley, president and chief executive of Royal Caribbean International, said: "We made our commitment to making clean power at sea a reality – and soon the norm – when Icon-class was first announced in 2016, and we’re excited to see construction under way on what will truly be a ship unlike any other.