P&O Cruises oldest ship Oriana is to leave the fleet in August 2019.

The 1,880-passenger vessel joined the UK cruise line in 1995 and has been marketed as providing “traditional cruising at its best”.

But a 50-night Caribbean, Mexico and US cruise was cancelled in January due to “technical maintenance” required for Oriana.

The disposal of the 69,840-ton vessel follows P&O Cruises selling small ship Adonia to rival Royal Caribbean Cruises to be operated as Azamara Pursuit for its destination-focused line Azamara Club Cruises from August.

The departure of Oriana, the smallest ship in the fleet, follows P&O Cruises ordering two large, 5,200-passenger ships.

The first, named Iona, is due to enter service in 2020 and will run on Liquefied Natural Gas. The second as yet unnamed 180,000 ton ship is set to join the fleet in 2022, giving a 50% hike in capacity in five years.

Meanwhile, Aurora will be refitted next spring, prior to being re-launched as a ship exclusively for adults. New cabins will be added as well as fixtures, fittings, soft furnishings and enhancements to public spaces.

The line plans three key areas of investment in shore excursions, dining and entertainment across mid-sized ships Arcadia and Aurora and Oceana as well as the larger ships Britannia, Azura and Ventura from summer 2019.

P&O Cruises senior vice president Paul Ludlow said: “With the introduction of Iona in 2020 followed by a similar ship two years later, it is also imperative that we continue to elevate the standards of the rest of the fleet.

“Our research with current and prospective guests shows that their holidays need to give them a vital boost to their everyday lives – they tell us that they want ‘to live life at ‘100%’.

“Cruising today is perceived as a contemporary and aspirational holiday yet it is still one which has very small penetration in the holiday market as a whole. Our vision is to break these barriers by listening to feedback from our loyal guests whilst expanding the audience of new cruisers.

“The additions will include new excursions across our itineraries, new dazzling theatre shows and daytime activities which reflect today’s trends.

“We will be investing in Aurora’s refit next year; Food Hero Eric Lanlard has devised an entirely new afternoon tea for all the ships, which will be very special, as well as refreshed menus and cocktails across the fleet.”

The introduction of the enhancements will coincide with the departure of Oriana from the fleet in August next year.

Ludlow said: “Oriana is an original, and a much loved P&O Cruises ship.

“Whilst we will miss her, her departure will allow us to focus on our remaining mid-sized and larger ships as the fleet expands with Iona and her sister ship in 2020 and 2022 respectively.

“Oriana will be with us until August next year so there will be plenty of opportunity to celebrate her time with us.

“Those guests who have sailed on Oriana will then be able to enjoy holidays on Aurora and Arcadia, both of which are exclusively for adults and have a very similar on board feel, and experience the re-vitalisation taking place over the next year.”

A special final sailing by Oriana will be announced by the company shortly.

Further details of the new passenger experiences will be announced over the next year.