This is my first luxury cruise, my first cruise of any kind, and I need others to put Silversea's Silver Shadow in perspective. No theme nights or kids' clubs. And there are not 2000 of us lining up to board in Adelaide. Just 382 guests when the boat is full, plus 295 crew. Our cruise isn't full and the staff outnumber guests, although that only goes part of the way to explaining the extraordinary levels of service - staff who insist on carrying your porridge from buffet to table, who would follow you around the boat with champagne on a silver tray if you asked them.

We are, indeed, on a luxury ship, the essence of which is food - any time, anywhere, and pretty much anything that takes your fancy, all free, along with the booze. Twenty-four-hour room service, and a butler assigned to each room.

There's a boutique selling lovely European clothes, of the monied variety, another selling Euro-bling jewellery, a gym where trainer Slobodan holds small yoga, Pilates and stretch classes, and a spa for the beauty treatments you will need, since there's a dress code which clicks into place at 6pm each day and it's rather proscriptive, all the way up to the dinner suit and gown you wear on ''formal'' evenings.

There are loads of astonishing artworks lining the walls. Picassos, Salvador Dalis, Miros, a string of famous photos of Marilyn Monroe. They're for sale and many of the Picassos and Marilyns, which are the ones we want, seem crazily affordable at prices of about $8000 or so. Hell, we almost buy one. We're among the rich crowd, the captains of industry and you can get a little grandiose in this company, especially when your head is spinning with the sea.

There's a library where you can work your way eruditely through books on American politics, or fill spare hours between beauty treatments and eating by reading Patricia Cornwell and Janet Evanovich. Since this is nothing remotely like a shopping mall - ships sway, I've discovered, no matter how gentle the ocean - Evanovich gets me through many prone hours in my suite. That and the lectures.

You'll know the name Terry Waite. The guy who in the '80s spent almost five years as a hostage of Hezbollah in Lebanon, chained by hands and feet to the wall, alone in a room for 23 hours and 50 minutes a day, the outside world unaware of his whereabouts, why he had been taken or even, for most of the time, the fact that he was alive.

Well, he has washed up here, a regular guest lecturer aboard Silversea cruises. And each day he delivers another heart-stopping account of the lead up to his capture, when he was a representative of the archbishop of Canterbury and found himself negotiating the release of hostages, then those years in captivity, and his final release. He's a polished speaker with an astounding story. And I can't help wondering why he chooses to be confined for weeks on end on a cruise boat each year, where there is no escape, other than welcome days at port. But Waite clearly has his sea legs, and for people like him, being out on the ocean, nothing but vast sea, might well feel more like freedom than captivity. Not for Maggie Beer, I think. She is here also, entertaining us with a cooking demonstration and talks.

This is Beer's first cruise. She took the gig partly because she and husband have been thinking about a cruise in the Baltic and she figured a trip across the Great Australian Bight might be a good introduction. Well, it looks like the Baltic option is off the table. Not that Beer doesn't enjoy her time - she has the kind of joyous personality quick to laugh and take pleasure in everything - just that she is a person rooted in the Barossa and in the land.

The cruise is 19 days from Auckland via Sydney and around to Fremantle. We board in Adelaide for the last six nights, including three nights at sea to cross the Bight, a notoriously rough patch of ocean, where we have unnaturally calm weather.

Slobodan laughs at me wearing the acupuncture sea bands during his stretching class. ''We're not moving!'' he says. I'm not sure who gets the last laugh as I stumble to my feet and out the door to throw up during the sit-ups. Hotel director Flavio Gioia is equally nonplussed by my state. He loves a robust ocean, he says, when the ship's pitching up and coming down, there's a crash as something falls, and the waves are whacking against his office window on the fifth deck. ''I love it, I really love it,'' he says. Exhilarating stuff. The exhilarating parts for me are the two days in port, at Port Lincoln, a fishing town focused on tuna farms, and Albany near the bottom tip of Western Australia, a town packed with early colonial history. Both are very pretty, apparently prosperous, quiet and removed from the madness of the east coast.

For director Gioia, 47, home is Udine, in Italy's north but he clearly has a wandering spirit, leaving for London at 19, and later spending seven years each in New Zealand and Australia, on Hayman Island. Gioia has been on cruise boats for eight years, three with Silversea. He spends four months at sea, then two months off - after four months, he needs a break, but before long he's itching to get back. It's one of those things - can't live with it, can't live without it. Non-senior crew spend six months at sea before two months off.

As to the customers, he says well over half are return cruisers, some clocking up phenomenal time at sea. Two couples have 700 days, he says, and one has 1300 days. I meet a British woman who has been cruising with Silversea for 17 years, two or three times every year. Well into her 70s or older, tiny and bird-like, her long grey hair thinning, and her clothes and jewellery impeccable, she seems to embody something about this European liner.

''What is the appeal of cruising?'' I ask Gioia. ''It's the feeling of camaraderie,'' he says. ''In the end you're all on the same boat going in the same direction. You're all away from your normal life and going somewhere together.'' Yes indeed, and when cruise director Kirk makes his peppy announcements in that leap-up-and-punch-the-air American accent, I feel like I'm on a summer camp of enforced cheer. Which morphs into cabaret when Phoenix takes the stage for his ''psychological entertainment'' shows. Actually, Phoenix is not the showy magician you might expect - he's a quietly-spoken Australian who insists he's not psychic, but simply using the power of suggestion for his tricks. He also treats us to a memory workshop where we learn how to remember long lists of items and people's names.

Interestingly, attendance is low, with fewer than a dozen people up for memory games, and the average age here is well below the average age of the ship. ''Who are Silversea's regular customers?'' I ask Gioia. Very affluent people who enjoy a vacation in the right setting, he says. And usually retired. ''What about younger people? Don't you need to get them on board too, perhaps by something radical like dropping the dress code?''

''Don't you like dressing up?'' he chides. ''It's what makes cruising cruising. People love the formal nights and a lot of people would hate to see the formal nights go.''

Formal evenings on the Silver Shadow are the full event - dinner suits or dark suits for the men and evening gowns or cocktail dresses for women. We wear the gear and sway down the corridors to our favourite Italian restaurant on formal night. We love this place for its Italian sensibility - pasta made each day by a chef from Milan, and served with simple, clinging sauces; the osso bucco rich and gelatinous, the bone marrow ready to be lifted out of the bone; and the fagioli, the Italian bean and pasta soup, here thick with mushed-up beans and just a little pasta. Tablecloths are Frette, Italian and all cotton (and back in bed, there are goosedown pillows to rest your head); glassware and plateware is German-made.

Portion sizes are perfect, and one of the things about being on an Italian boat is that the food, along with everything else, appears to be largely European-sourced.

The Silver Shadow has four restaurants. On the pool deck you get pizzas, and steaks on sizzling tiles, for which they clip your napkin around your neck and you feel like a giant baby.

The most upmarket is a 24-seat degustation restaurant, with the imprimatur of Relais and Chateaux. Here, the service is stepped up yet another notch, with four or five staff in a tiny space. The plates are gold-ringed, the cutlery is copper, and the cloches are removed with a flourish - un, deux, trois, et viola! You order wine off a list (and pay, although presumably because of freedom from Australian tax rules, some very good wines are $80 or less), and Pol Roger starts at $40. We would have ordered this if they weren't popping the cork off a bottle of champagne as we sit. Gioia says Silversea was the first to make cruises all-inclusive (including tips). Yes, you pay upfront - you could cruise for a week on one of the big ''cash cow'' boats for the price of a day on Silversea, Gioia says, with some exaggeration (back of the envelope calculations suggest a Silver Shadow cruise might cost upwards of $1000 a night for a couple, whereas you can hop on cheaper boats for more like $350), but you can also disembark with nothing charged to your credit card (although you can soak up dollars on the super-slow internet and on phone calls, since you're quickly out of range of shore-based communications).

I meet with Gioia after four nights at sea, and he assures me I would have my sea legs within a week. I don't believe him.

But after a day on solid ground in Albany, I'm feeling good again, and that night I abandon the seasickness pills. And I'm OK. Sure, my head hurts and I can't face alcohol or Slobodan's Pilates class, but I'm eating again. Could I get used to sea life after all?

Nah, who am I kidding.

Kirsten Lawson and partner were guests of Silversea. The Silver Shadow next visits Australia in January and February for three 14-night cruises: Sydney to Auckland, taking in the coast of New Zealand, priced from $13,800 a couple to $50,200 for the most expensive suite; the same journey in reverse (same prices); and Sydney to Bali along Australia's east coast ($12,000 a couple to $38,200 for the top available suite). silversea.com