(3:15 p.m. BST) -- The Danube is now the most popular river cruise destination, overtaking the Rhine which slips to number two, figures released today by the Cruise Lines International Association (CLIA) in its 2018 River Cruise Review revealed today.

In third place is the Douro river in Portugal, which experienced the highest growth, showing an increase of 15 percent in passenger numbers.

The UK and Ireland river cruise market grew at a healthy pace in 2018, reaching 232,000 passengers, an increase of 10.4 percent against 2017.

Andy Harmer, CLIA UK and Ireland director, said: “The river cruise market is proving popular in the travel sector, with passenger numbers continuing to grow year on year. The can be put down to the incredible experiences a river cruise has to offer, as guests can sail through the heart of a destination – as well as the plethora of fantastic itineraries and the high standard of the ships.

"With 18 new vessels set to launch from now to 2020, guests can sail on ships that are contemporary, luxurious and have plenty to offer. This attracts the modern-day traveller, who seeks to explore the world in comfort and style."

Europe remains the most popular region, with Central and Western European destinations taking the largest share of the market at 64 percent.

207,000 river cruises were taken on a European river, up from 188,700 in 2017, with the average length of a river cruise in Europe increasing slightly to eight nights.

On non-European rivers, passenger numbers grew by 13 percent, from 21,700 to 24,600. These cruises had an average length of 6.7 nights, an increase of 3.1 percent from 2017.

Asia, in particular the Mekong, is the main river cruise destination outside of Europe, while the Nile was another big performer with an increase of just over 21 percent from 4,700 to 5,700 passengers.

River cruises in Asia accounted for six percent of the overall market share.

The best performing regional markets compared to 2017 were North America – a relatively new destination for river cruising -- Africa and Central Europe.