The world of holiday-making, as you probably know, can be said to be divided into those who take sea cruises, and those who haven't yet wised-up to the matchless value cruising offers.
Let's assume you're in the wised-up corner.
Maybe you've done a few cruises, perhaps the Med, the Baltics even, or been more adventurous and gone farther afield, Alaska or New England.
Who knows, we may have even met - in which case, 'Hi! Hello, good to see you again.
Fancy a coffee or a drink, while I bore you mindless about river cruising?' The fact is, if you've never considered river cruising you could be in for an extremely pleasant surprise.
For a start there are loads of rivers to choose from.
Naturally it's a different world from sea cruising.
The superlative luxury of modern sea cruise ships simply can't be emulated within the confines of a river vessel.
The star ratings used are totally different.
That said, the best quality river ships are extremely comfortable, luxurious even.
The food's good, the service excellent.
It's just that ocean-going cruise ships have put practically everything else, including 5-star hotels, in the shade.
Some people, of course, have a hang up about rivers.
To them, rivers smack a bit of 'Wind in the Willows' and 'Three Men in a Boat'.
And have you ever heard the phrase 'ditch crawling'? It's the sneering remark made by yachtsmen about any river craft activity.
They can sneer all they like.
You should worry when you're sunning yourself on deck, taking it easy, watching the world go by.
And going by so close you could physically almost touch it.
One moment you're on the blue Danube, eyeball-to-eyeball with a herd of friendly Friesians, and the next minute you're in the centre of Salzburg listening to the magic of Mozart in his hometown.
Or maybe you're on the Douro in the heart of Portugal's vineyards.
The variety is huge.
From the Dutch bulb fields in spring, to the special magic of Rhineland Christmas Markets cruises, there is a world to choose from.
The scenery and the sheer unequalled charm of river travel is bewitching.
The grandeur of the Rhine, the lure of the Lorelei, the delights of the Moselle, I could go on.
A river cruise can be a magnificent holiday.
If you're fascinated by locks and waterworks; by wonderful villages, intriguing towns and historic cities, all being delivered daily to your gangplank, you will love it.
Remember, too, almost everywhere you go, you step off into the heart of the action, centre ville itself.
Avignon, Basel, the Camargue, Cologne, Koblenz, Lyon, Paris, Opporto, Venice, the names ring out like a peal of welcoming bells.
And between times, you're in a calming world, a tranquil place of peaceful valleys, filled with more sheep than people.
Bear in mind too, that many river cruises are no-flying, by travelling Eurostar or by le shuttle.
So there you have it.
It's not rivers versus sea cruises.
It's sea cruises and river cruises.
And how many rivers are there in the world? Fewer than you think: 165 major rivers.
There are thousands of lesser ones, of course, but no one has ever done a complete survey.
I don't blame them and, anyway, we'd be talking canoes!