The old railway bridge loomed ever closer as the ship’s captain advised me: ‘Please mind your head sir.’
I sensed it was only a precaution.
But the underside of the bridge was a mere six inches above the top of my head as I stood on the top deck while we passed underneath, so he was probably right to issue the warning.
It was another lesson in how river cruising differs markedly from the maritime variety.
Forget those long days at sea with nothing on the horizon – on the river you are assailed by new sights at every turn.
These include bridges of every design and age. We must have passed beneath a couple of hundred on our journey from Luxembourg through Germany to Nuremberg on the rivers Moselle, Rhine and Main.
And then there are the locks – a total of 53 to be negotiated at regular intervals, each posing a test for our Hungarian skipper as he nursed the 360ft long Amalegro into and out of the chambers with just a few inches to spare on each side, watched every time by fascinated passengers.
But the most stunning views were of the steep-sided river banks of the Moselle and Rhine where countless vineyards snake upwards at seemingly impossible angles, and Gothic castles peer down from their defensive positions at the top of the valleys.
This was the essence of our voyage, and it is easy to understand why European river cruising is such a fast-growing sector of the holiday market, attracting passengers from all over the globe to the wide open river road that stretches all the way from Amsterdam to the Black Sea, connecting 15 countries over its distance of 2,220 miles.
Add in the numerous stops at historic villages, towns and cities along the way and you have an experience that will increasingly give sea cruising a run for its money.
Joining the Amalegro in the small Luxembourg town of Remich on the Moselle, we were immediately made welcome by our Bulgarian cabin stewardess.
Our first port of call the following day was Trier, the oldest city in Germany with an impressive array of Roman remains including an amphitheatre, baths and the famous Porta Nigra, the best preserved Roman city gate in the world.
It was the first outing for what the cruise staff called our ‘devices’ – mobile phone-sized units with headphones which pick up the tour guide’s words of wisdom within a range of about 30 metres – so you don’t need to stay close by her side.
Back on board we positioned ourselves in comfy chairs on the top deck for an afternoon cruise along the idyllic Moselle valley, its lush vine-clad slopes ascending from the meandering waterway.
The Romans first planted vines in the fourth century, and these days some top-quality Rieslings originate here.
More traditional riverside treats lay in store the following day when we visited charming Miltenberg and Wertheim.
Our last full day included a tour of historic Bamberg, designated a Unesco world heritage site, which is home to nine old-fashioned breweries.
After a farewell dinner and some furious packing of suitcases, it was time to enjoy a few nightcaps in the bar with newfound friends from English-speaking nations around the globe.
At the crack of dawn the ship berthed just outside Nuremberg and the adventure was over.