All these years later, I've lost count of how many wonderful trips we've had on board a variety of fabulous ships. I often give lectures about the royals on the Cunard ships. It can be quite a daunting experience, as the theatres seat hundreds of people — and you always have your fingers crossed for a full house.
Luckily, folk of almost all nationalities seem fascinated by our Royal Family. I tell them all the crazy things that happened when I travelled the world as the BBC's Royal Correspondent: President Mandela's infectious excitement when the Queen visited South Africa — and her joy at meeting him; Diana's landmine mission in Angola; and the rollercoaster of reporting on the War of the Waleses. Americans, in particular, like to know every detail about William, Kate and, of course, Harry.
But, for me, the real joy of cruising is that it takes so much of the hassle out of seeing the world.
After the initial journey to join your ship — which may involve the stress of air travel and almost certainly the horror of holiday traffic on the motorways — you can unpack, unwind and let the world come to you.
After an evening of fine wining, dining and possibly dancing, you wake up refreshed and marvel at the sight of a new country, island or city that has arrived at your door.
I have woken to the sound of sea lions barking at Puerto Vallarta in Mexico and stood on the balcony in my nightie just after dawn as we arrived at the entrance to the Panama Canal. Seeing the Statue of Liberty for the first time as we glided gently into New York after a six-day Atlantic crossing was sheer magic.
Yet nothing beats that initial peek at your destination for the day: yours to explore as much or as little as you choose.
But even though the industry is expanding rapidly, with more than 20 million passengers a year, some myths about cruising persist. Let me debunk them for you.
Myth: We'll be cooped up like sardines
Well — first of all, it's certain to be a pretty magnificent tin. The sort of place that most of us would love to live in. And, beyond that, there's almost always a sense of space and a variety of quiet corners.
Most ships have impressive libraries with luxurious leather armchairs where you can relax in peace. Some have crossword corners — peaceful spots where you can try your hand at the daily crossword in the ship's newspaper — and huge jigsaws scattered about to stop at, ponder and maybe add a piece or two.
Out on deck, there are plenty of sun-loungers, so you won't be sunbathing cheek by jowl. And, of course, there's always the privacy of your own cabin — or stateroom, as they're often called — where you can chill out in front of the TV or, better still, watch the ocean glide by.
Myth: All the food will make me fat!
There's no getting away from the fact that you can eat and drink from the moment you wake until long into the night, all the while topping up with room service.
But after the initial novelty of having so many delicious treats on tap, Jim and I find we generally gain no more than a pound or two on cruises.
We make it a rule never to be tempted by the amazing desserts — but we indulge liberally in everything else. And the standards are usually extremely high.
Sometimes, in the Caribbean, the crew will organise a barbecue on the beach. In the top-grade Grill restaurants on Cunard's three Queens, you can ask for pretty much anything you want — and often the maitre d' will cook it at your table.
Myth: If you've done one you've done them all
Nothing could be further from the truth.
There are so many ships and destinations, each offering something different. In recent years, my husband Jim and I have been lucky enough to holiday on the largest full-rigged sailing ship in the world — the Royal Clipper — which gave us a really unique experience.
You can climb the mast, help hoist the sails or simply admire the beauty of an exquisite tall ship.
We've visited Australia on Queen Victoria (which feels a little bit like home to us) and, last month, we went on our first river cruise down the Rhine aboard Uniworld's SS Antoinette, which turned out to be very luxurious indeed.
When Jim and I went on our very first cruise all those years ago, we were astonished that so many of our fellow voyagers had notched up dozens of cruises. But, now, we understand why. And what's more, we count ourselves as life members of that happy band of travellers.
Myth: It'll be just like Butlin's
There's certainly a similar sense of joy, conviviality and fun about cruising, but you never feel as if you're being corralled into taking part in any of the activities.
The options are set out in a daily news sheet from which you can pick and choose.
And there's so much you can learn: many ships have lecture programmes about the history, arts or culture and politics of the places you're visiting. You can learn to paint, dance, ice-skate, play croquet or go wall climbing.
My perfect day on board is to have breakfast on the balcony, then go to the line-dancing class (always a huge laugh), relax, read, enjoy a light lunch, go for a swim, then run for a mile or so around the jogging deck before a yoga class — followed by sundowners on the balcony and dinner in one of the restaurants.
Myth: I'll soon get bored of it
Boredom is not an option. There are so many ports of call to explore and on-shore adventures to be had.
In Santorini, Greece, we hired a quad bike and raced around like teenagers. In Bonaire, in the Caribbean, we began to believe we really were teenagers and hired a huge Harley-Davidson — only to find neither of us could reach the brake pedal!
In Germany recently, we went on a tour that took us to a vineyard where they make organic vinegar — so good you can drink it as an aperitif.
And on one of Azamara's smaller ships, which specialise in staying late in port so you can enjoy the nightlife, we were all guests at a private classical concert in the ruins of the openair theatre of Turkey's ancient Ephesus — truly magical.
