Tom Wolber, president and chief executive, said the design of the vessels – the first of which is expected for delivery in 2022 – was “currently being perfected” and would feature “lots of new elements, but with all the aspects that made Crystal great in the first place”.

“We are not going to give up promenade decks because we need more indoor space – we figured out how to do it,” Wolber told guests at its annual Sales Gala for top-performing trade partners this week onboard Crystal Serenity.

Wolber announced during last year’s event that the ship would decrease to approximately 67,000 gross tons to accommodate around 800 guests, down from 1,000 under his predecessor Edie Rodriguez.

The line announced the building of three new ocean ships in 2015.

In his update last week, Wolber said: “The ship has grown a little bit, as well as the stateroom sizes."

However, he declined to comment on further details. “I don’t like to make promises I can’t keep,” he added.