Oceania Cruises’ Sirena has marked 25 years in operations.

Originally built for Renaissance Cruises, the vessel was delivered by the Chantiers de l’Atlantique shipyard on Oct. 22, 1999.

After a christening ceremony in Fort Lauderdale a few weeks later, the ship kicked off its maiden season in the South Pacific as the R Four in December 1999.

Sailing from Papeete, the vessel initially offered cruises to Tahiti and French Polynesia on a year-round basis.

When Renaissance Cruises ceased operations in 2001, the R Four remained laid up for over a year before being sold to Princess Cruises.

Renamed Tahitian Princess, the ship continued to sail in the Pacific Ocean, later adding itineraries to Hawaii, Australia and Alaska.

To reflect its new deployment on worldwide itineraries, the ship was renamed once again in late 2009, becoming the Ocean Princess.

Five years later, in 2014, Princess Cruises announced an agreement to sell the 710-guest vessel to Norwegian Cruise Line Holdings.

After completing its schedule for the Carnival-owned premium brand, the Ocean Princess was handed over to its new owners in March 2016.

Following a 35-day, $40 million refurbishment, the 30,200-ton vessel debuted as the Sirena for Oceania Cruises.

As part of the refit, the ship introduced new features for the company, including Baristas, the cook-to-order grill at Terrace Café and two new specialty restaurants.

After welcoming Oceania’s guests in April 2016, the ship has been offering cruises to various parts of the world.

The Sirena is scheduled to start 2025 in the Caribbean before repositioning to Europe for a summer deployment that includes itineraries in the Mediterranean, Scandinavia, the British Isles, the Baltic and the North Sea.

Upon completing the six-month deployment in the region, the vessel will reposition to Asia and the Indian Ocean via the Canaries and the African west coast.