Many companies offer specialised cruises, typically dedicated to cooking, wine tasting, music, theatre, history, politics and sport

private balconies are much in vogue.

Some ships squeeze in three restaurants, but evening activities tend to be limited to a lecture on the next day’s programme, a resident pianist, or regional entertainers joining for a few hours. Emerald River Cruises has introduced an indoor pool with a roof that folds back, becoming a cinema at night.

All river ships have large, unencumbered top decks suitable for sunbathing, the occasional buffet dinner and, sometimes, a pool. But the design has to be clever, and as economical with space as possible. This is because the vessels have to pass under bridges when rivers are flowing at their peak – usually this problem occurs in the winter, but not always. Squeezing underneath when the water has risen to its maximum level can prove entertaining.

It’s impossible to get lost on a river cruiser, as it comprises only three decks and a single corridor between the cabins. Embarking and disembarking could not be simpler, as the boats often dock in the centre of a city – Dusseldorf or Avignon, for example. Amsterdam is at the head of the Rhine, but also the starting point for trips through the Dutch canals and the Elbe. The port of Amsterdam is close to the city’s main railway station, with the big sea-bound ships nearby towering over you in comparison.

In a survey carried out for the Cruise Lines International Association last year, one of the questions was: “Which is of greater importance to you, the quality of the facilities or the choice of destination?”The ship and its facilities topped the poll with ease. So make sure you choose carefully.