"Mum, there’s a naked man in the sauna.”
My 14-year-old daughter Dani lets out an anguished shriek as she dashes over, her face a mask of horror.
I can’t help laughing at her mortified expression and gently explain that our fellow German passengers don’t have the same inhibitions as we Brits when it comes to stripping off in public.
But it’s one of a number of cultural differences that come to the fore during our week-long family cruise along the Seine with German line A-Rosa.
We’ve been tempted aboard by the line’s family-friendly offer of free child places for under-15s along with benefits of the Premium Package that include free drinks and, thanks to a tie-up with Cosmos, complimentary home/airport transfers.
And while we may be sailing through northern France, the ambience on A-Rosa Viva is definitely Teutonic, led in part by A-Rosa’s Rostock roots and mainly German-speaking clientele, diluted marginally by a handful of Brits and a few Spaniards.
It makes for a novel combination and is quite unlike the mainly American feel of most other river cruise lines. Even the decor is markedly different: bright and breezy with vivid reds and oranges, giving the ship a warm, summery glow.
Everything seems to run with Germanic efficiency, although the buffet-style dining injects flexibility at mealtimes as we can eat when and where we like.
Admittedly, the absence of waiter service here risks making dinners less of an occasion, but our trip coincides with a summer heatwave, so we eat alfresco at every opportunity.
Spending balmy evenings dining on deck is blissful, and the same goes for breakfast and lunch. In fact, this becomes one of the most enjoyable and memorable parts of the cruise.
The cuisine is tasty and refreshingly different, reflecting healthier continental tastes rather than ubiquitous burgers, pizza and chips.
In addition to a surfeit of fish dishes, including perch and pike, there are braised pork cheeks, calamari and chicken dishes, plus a good selection of salads. In fact, there’s no shortage of culinary temptations.
Desserts are less varied, with ice creams and mousses most common, much to the delight of Dani and her twin sister Holly – along with crepes and cheeses from all corners of France.
A more formal alternative is the speciality 32-seat French brasserie, where we enjoy a five-course feast with accompanying wines, costing €42. But as we’re on the Premium Package, not only are most drinks included during our cruise, but this grand dinner costs just €14.50 extra.
German is naturally the primary language onboard, but our softly spoken multi-lingual hostess, Jennifer, acts as a translator for announcements and on selected shore excursions.
Twelve excursions are offered, ranging from a walking tour of Rouen (€19) to an afternoon coach trip to Honfleur (€79).
The only catch is that they’re nearly all in German, which rules them out unless Jennifer attends, although when there are more British passengers, English-speaking tours are organised.
With a fleet of mountain bikes onboard, and cycling excursions offered at each stop, we’re keen to strike out on two wheels so my husband Geoff and I ride off to visit Rouen’s historic treasures. There are no children’s bikes, however, so it’s worth alerting families that kids might not be able to join in.
As I bump across the cobbles of the Old Town, it seems an ideal way to explore and we’re soon ticking off the main sights: the Notre Dame Cathedral, whose spire reaches higher than 150 metres and is said to be the tallest in France; the striking Church of Saint-Maclou; and Gros-Horloge, a beautifully restored astronomical clock whose gilded face is full of exquisitely decorative detail.
The following morning we retrace our route on foot with the girls as I’m keen to take them to Place du Vieux-Marche, the market square where Joan of Arc was burnt at the stake by British soldiers in 1431 after being found guilty of heresy. She was just five years older than the twins.
We stand in silence, absorbing the spot where she was martyred, now marked by a cross in front of the modern Church of St Joan of Arc, its distinctive roof shaped to replicate the flames of the stake.
Back onboard, we head to the spa, positioned right at the prow – the best I’ve seen on any river ship and another German influence, I suspect, with its pocket-size gym, sauna, treatment rooms and relaxation area.
But the main temptation is the hot tub on the adjacent outside deck where I sit amid the bubbles to watch the riverbanks pass by.
This becomes a popular pastime for us all, and while we’re sometimes greeted by more naked flesh than we expect as we pass through the relaxation area, a sign by the hot tub advising users to wear “appropriate clothing” prevents any unwelcome surprises there.
But cultural sensitivities apart, some of the Germans we encounter speak good English, talking to us about life in Britain and curiously asking about Brexit.
It adds to the house-party feel of this cruise where entertainment is restricted to quizzes, a resident DJ and a singing duo who come aboard one evening.
There isn’t anything laid on for children on this sailing – A-Rosa’s Family Cruises tend to be on the Rhine and Danube (although they’ll be added on the Rhone and Seine in 2018), but the crew are friendly and accommodating and our family-friendly cabins with their interconnecting doorway are certainly convenient.
Besides, the girls are happy to occupy themselves and it’s easy to go with the flow as A-Rosa Viva wends its way through Normandy’s gentle countryside of rounded hills, punctuated by solitary settlements of half-timbered houses, clustered around medieval churches with soaring spires.
Sleepy Les Andelys is one of our favourites, where we climb up to the ruined fortress built by Richard the Lionheart on the rocky cliffs overlooking the town to admire the views, before going for a dip to cool off at a nearby open-air swimming pool.
From Vernon, we pay homage to its poster boy, impressionist painter Claude Monet, on a visit to his former home at Giverny, to gaze at the waterlilies and Japanese-style bridge in the famous gardens he immortalised on canvas.
Back in Paris on the last day, we join thousands of visitors crowding into Versailles but our evening coach tour of the capital is more relaxing with twinkling lights illuminating the Eiffel Tower, adding a sparkling finale to a memorable week.
Book it: A-Rosa offers free sailings for children under 15 on all departures – one free place for every full-fare paying adult. A one-week Seine cruise costs from £3,400 for a family of four, departing on October 20, 2018. This includes flights, drinks and private home/airport pick-up service.