Location: Riverside Mozart is twice the width of traditional river ships so can only sail the Danube, where locks are wide. Cruises are three to 14 nights, mostly from Vienna or Budapest.

First impressions: Riverside Mozart looks a million dollars, which is probably a fraction of what former owner Crystal Cruises spent in 2016 refurbishing what was then called Crystal Mozart. Indeed, it looks so good, new owner Riverside hasn’t changed a thing. The furnishings, fabrics and fittings are akin to those in a top London hotel, with plush sofas and chairs, designer light fittings, and suites finished in marble, velvet and silk. Taittinger champagne is served as standard.

The facts: The vessel is one of five former Crystal Cruises river ships snapped up by Riverside Luxury Cruises, a river cruise line launched by German hotel company Seaside Collection. Riverside Mozart debuted in its Riverside colours in April. With six places to eat, the biggest suites on Europe’s rivers and more than enough room for 160 people inside and out, Riverside Mozart offers the luxury of choice and space.

The Marketplace, Blue, the Bistro and sundeck BBQ are variously open for breakfast and lunch; for dinner it’s Waterside. There’s also the exclusive Vintage Room, which holds 12 people and costs €295 for seven courses with wine, or tapas in the bistro. Entry-level suites from 219sq ft are a third larger than on traditional river ships.

Penthouses, a third larger again, have walk-in wardrobes and bathrooms with separate showers and bathtubs. The sole Mozart Suite, which comes with free laundry, limousine transfers and other perks, is twice the size of a penthouse and can be combined with the suite next door for even more room.

All suites are beautifully finished and come with butler service. There are no step-out balconies and the Toto toilets that Crystal added are beyond irritating, gurgling and opening as you pass (the butler can show you the off switch). Fitness fans will love the 30 bikes for passengers to borrow and the Technogym equipment in the gym.

Ideal for: Target luxury ocean cruisers tempted to try the rivers but loath to give up on space and dining choice, as well as non-cruise clients and city-break lovers prepared to pay for the best. English is the first language on board.

Wow: The spa on Riverside Mozart is large and exquisitely furnished. It has a huge indoor heated current pool, sauna and steam rooms, and a relaxation area with views of the river. There are massages, mani-pedis and more.

Book it: A seven-night Treasures of the Danube cruise round-trip from Vienna departing on October 20 this year costs from £2,660, including transfers, drinks, excursions, tips and Wi-Fi. Flights are extra. riverside-cruises.com