Spanish yard Barreras has clinched the second in a potential series of three luxury cruiseships for the Ritz-Carlton group.
The yard said the new vessel would be hull number 1706.
The first vessel was agreed in 2017, with two options attached.
Delivery of the initial unit is due in the fourth quarter.
No price has been revealed.
The yard has called the design - in cooperation with the owner and Tillberg Design of Sweden - "amazing".
The Maltese-flagged vessels will accommodate 544 people, including 298 passengers in 149 suites and 246 crew members, with a maximum speed of 17.8 knots.
Ritz-Carlton is teaming up with Oaktree funds for the project.
