If I tell you a story about a swimming pool that turns itself into a cinema, it might sound like one of the fairytales from the romantic German region I was sailing through at the time, or just plain cuckoo like one of the area’s famous clocks.

Restricted in size by low bridges and narrow locks, most river vessels look pretty similar on the outside. Emerald Waterways has broken the mould with a ship that is very different on the inside, one that could persuade river cruise virgins to step aboard and experience the fastest growing sector of the cruise industry.

Last year 109,900 people in the UK took a river cruise, a 22 per cent increase on 2012. This year more than 30 new vessels are being launched to cater for the demand and Emerald Sky is one that stands out from the crowd.

The 182-passenger Sky got off to a suitably stylish start in April when it was christened in Amsterdam by British style icon Twiggy. Sailing on the Rhine, Main and Danube rivers, it has a relaxed and easygoing atmosphere, with none of the formal nights associated with ocean cruising.

Recently joined by sister ship Emerald Star, the vessels are part of Australian-owned Scenic Tours and launched as a budget alernative to their all-inclusive Scenic Cruises that took to the rivers in 2008. While the prices may be much lower, Sky is certainly no poor relation, with plenty of standout features and the feel of a floating boutique hotel.

Our week-long cruise took us from Amsterdam to Basel. We sailed through the Dutch countryside passing windmills and then castles as we entered the Rhine. The first evening onboard introduced us to some of Sky’s contemporary features, including the liberal use of glass, mirrors and cool fibre-optic lights that form the centerpiece of the airy atrium.

The Horizons Lounge, the main public area, boasts a funky mix of tables and chairs, with none of the uniform look found on other ships. The shiny black bar with strobe lighting is a focal point, with a row of bar stools looking over the front of the ship, a perfect spot to watch the world float past. Artwork has been installed by a Dutch company called Oasegroen, and features exhibits made with sustainable items such as petrified wood and marlin teeth beachcombed from the seashore.

This leads to a sheltered al fresco terrace and upstairs is the sun deck, with a walking and jogging track, mini golf and a barbecue area (what else could you expect on an Aussie-owned ship?) that is used for lunch at least once a week (European weather permitting!).

A stroll towards the back of the vessel took me to the “wow factor” moment. By day there is a lovely blue mosaic-tiled pool, that’s big enough to swim in, with panoramic windows on three sides and a retractable roof. There are comfy loungers and chairs with a bar in the corner serving everything from ice cream to Champagne.

When guests are at dinner the clever part starts. The floor of the pool rises to create the floor for the cinema – the first dual-purpose space of its kind on a river vessel. Bowls of popcorn await cinemagoers, with three films screened each week. Entry is free on a first-come first-served basis.

Food and cruising go hand in hand, and Sky doesn’t disappoint. Buffet-style breakfast and lunch are served with an extensive choice of hot and cold dishes, followed by a waiter service evening meal in the main dining room. Dinner includes a choice of starter, soup, main course and dessert and there’s always a vegetarian option, plus steak or salmon always available. The captain’s gala nights include a couple of extra courses.

Cabins come in four different categories. My panorama balcony cabin featured a nifty floor to ceiling window that dropped to halfway at the touch of a button, creating the feeling of being on a balcony.

The week slipped by all too quickly, days interspersed with delicious meals, excursions included in the price of the cruise and some optional tours for passengers who want an extra dose of culture.

We wandered around cobbled wine towns such as Rudesheim and Koblenz, explored Cologne’s magnificent Gothic cathedral and heard the legend of the Lorelei Rock, where sirens lured passing sailors to their doom. Our last day was spent in the Black Forest, taking a step back in time at the open-air museum that recreates 16th century life and sampling Black Forest Gateau. Expanding waistline included, the week sailing through this picture postcard region really was a feast for all the senses.

So if you are new to river cruising, or looking for a new river cruise experience, Emerald Sky could just be the thing to float your boat.

• The facts

• Emerald Waterways offers the eight-day Jewels of the Rhine cruise from Amsterdam to Basel from £1,195 per person, based on two sharing, including flights, all meals, wine, beer and soft drinks with lunch and dinner, one included shore excursion almost every day and all tips

• The cruises, which also operate in the reverse direction, run from March to October. Check the website for special offers and early booking deals. Call 0800 270 7017 or visit www.emeraldwaterways.co.uk.