Uniworld will roll out three “super ships” in 2020 to replace its older vessels sailing the Mekong in Southeast Asia, the Nile in Egypt and the Douro in Portugal.

But U by Uniworld, the first river cruise line to target millennial travellers, has cancelled its 2019 sailings on original ship, the B, and moved it to new itineraries in Central Europe next year.

The B which was launched last year will now join sister ship the A, on central European rivers where there is better demand, said Ellen Bettridge, president and CEO.

U by Uniworld has struggled since its inception. It was originally launched as a brand strictly for millennials, but the company quickly removed its 18-40 age restrictions.

“Being the first means that we’re not only inventing an entirely new sector of the industry, but we’re quite literally in ‘unchartered waters,” Ms Bettridge said.

“As a brand, U will always stay true to its ethos as a sexy, fun, never-before-seen cruise experience, but we also want to remain open to consumer trends and feedback. That is how brands move from concepts to success stories,” she added.

The A will operate its 2019 itineraries as originally planned, the company said. In 2020, the B will sail from Brussels to Amsterdam and from Amsterdam to Frankfurt, while the A sails from Nuremberg, Germany, to Vienna and from Vienna to Belgrade, Serbia.

On its new fleet of “super ships”, Ms Bettridge said: “Our ships are absolutely unique and like a boutique hotel, reflect the destinations they serve from décor and artwork to food, beverage and programming.”

The new vessels include, the 84-passenger SS Satet which will offer 12-day Nile River cruises in January 2020. The ship will have three dining venues including an al fresco dining restaurant on the upper deck. There will also be a swimming pool and massage room. The SS Satet will replace River Tosca.

The 56-passenger new Mekong Jewel will offer a 13-day itinerary on the Mekong with stops in Vietnam and Cambodia starting from January next year.

The ship will have two dining venues including an al fresco restaurant on the upper deck. She will be constructed with eco-friendly materials with a water-cooled air-conditioning system to save energy. She will replace the Mekong Navigator.

The 100-passenger SS Sao Gabriel will launch on the Douro River in March next year. he will offer butler service and have Spanish and Portuguese cuisine. She replaces Queen Isabel.