RCCL’s move for a 66.7% stake in Silversea was this week granted final regulatory approval by the German Federal Cartel Office and the Austrian Federal Competition.

The group now operates 59 ships in total with a further 15 new builds on order. RCCL has promised to "accelerate" expansion of Silversea’s fleet and introduce some of its own in-house developments and technologies to make immediate improvements.

Silversea boss Manfredi Lefebvre D’Ovidio, whose father founded the line in the 1990s, will retain a 33.3% stake and remain executive chairman.

Royal’s acquisition is based on an enterprise value of $1 billion and will be financed through debt.

“We are excited to start working together, learning from each other, and providing even better vacations to Silversea guests,” said RCCL chairman and chief executive Richard Fain.

With the deal inked, RCCL and Silversea have announced Project Invictus, a multi-year initiative to significantly advance Silversea’s ultra-luxury offering.

The project will range from product enhancements to ship improvements, the first being an upgraded champagne and caviar offering on Silver Muse coming August 19.

Any such improvements will eventually be rolled out fleet wide.

The programme will also see the planned renovation of Silver Whisper in December extended, including a refit of all guest cabins.

Silver Wind will then undergo extended dry dock followed by Silver Shadow, which will take design cues from Silver Muse.