In 2013, water levels on the European rivers were at an all-time high, forcing many lines to cancel itineraries as ships were unable to pass under bridges.

Lines like APT and Avalon warned their passengers, many of which were forced to holiday on the rivers the following year.

But this year, it has been an unusually hot and dry European summer which has resulted in low water levels on estuaries like the Danube, Rhine and Elbe Rivers – some of the most popular rivers.

It’s believed that many people who will be travelling in September may be affected unless rains come to the rescue. Lines have been forced to find alternative transport for guests like by coach or staying in hotels rather than the ships.

Budapest in Hungary, an iconic destination on the European cruise route, was closed to river traffic last week.

Lines like Viking River Cruises has released a statement on its website saying, “While the unseasonably hot and dry weather in Europe resulted in low water levels on several rivers earlier this summer, recent rains have improved conditions significantly.

“As water levels continue to rise, most sections of the rivers are now stable, making sailing through possible. We expect most itineraries will resume regular operations in the coming weeks.”

Other lines like AmaWaterways which is a partner of APT, have been a bit more creative in their approach to the problem.

President Rudi Schreiner told Travel Weekly that when the sister ships, AmaPrima and AmaCerto were sailing towards each other, but couldn’t cross the upper Danube, the crew swapped ships while the passengers went on their shore excursions in Salzburg.

The guests returned to the same cabins, but on different ships in different ports to resume their journeys.

Mr Schreiner said ship swapping is a common practice when water levels were low. And the line also hosted guests in a hotel when they couldn’t dock in Budapest last week and were later bused to Vienna to embark the ship.

A spokesperson from APT and Travelmarvel said, “APT and Travelmarvel are currently initiating low water action plans when necessary, utilising ship swaps and amended itineraries where possible to combat any interruptions.

“The ability to perform these ship swaps provides minimal disruption to ensure guests are able to enjoy their river cruises despite the lower water levels. Local conditions can change quite quickly and both companies will continue to work with river authorities to monitor the situation.”