On 13 March 2020 a cruise ship called the Braemar was denied entry to the Bahamas after a number of its passengers tested positive for Covid. Forced to travel around the Caribbean, it was finally accepted by Cuba, from where those on board were evacuated to the UK.

The Braemar was just one of a number of cruise ships in which passengers found themselves quarantined at sea in those uncertain days. The Diamond Princess was stuck for a month anchored in Japan as the virus ripped through it, leaving more than 700 infected and nine dead. Another ship, the Ruby Princess, had 28 deaths. It was a nautical horror show.

Almost overnight these ocean-going symbols of leisure had become crucibles of death and contagion. Over the next 24 months, 35 cruise liners were sent to Aliaga in Turkey, the maritime graveyard where ships are dismantled and sold for scrap. Several major lines went into liquidation, and some observers suggested that the $150bn global cruise industry was effectively sunk.

Yet last week the Braemar, under a new name, left Belfast on the beginning of a three-and-a-half-year world cruise, heralding a new era in long-term cruises or, to put it another way, living at sea.

Having been bought in 2023 by a company called Villa Vie Residences, the liner is now named the Odyssey. Aside from the 125 passengers currently on board, the ship is also carrying a couple of heavyweight omens. Belfast was the port in which the Titanic was built and from where its fateful maiden voyage began. And the Odyssey is named after Homer’s epic poem in which its hero, Odysseus, famously spent 10 years wandering around the Mediterranean.

The Odyssey’s odyssey isn’t due to be quite so long, but the liner, which was scheduled to begin its cruise on 30 May, has already been beset by obstacles, much like Odysseus himself. Not quite a cyclops or the Sirens, but slightly more prosaic rudder and gear troubles. They added up to four months of repairs and left passengers to savour the summer delights of Belfast, a city hitherto uncelebrated for sunny blue skies.

“I’ve never had so much use for my umbrella in my life,” said Holly Hennessey, a “cruise addict” from Florida who had to move into a hotel in the city over the summer.

All told the voyage will last around the same amount of time as that between the last major lockdown and the present day. During that period the cruise industry has managed to stage a conspicuous comeback. Earlier this year, Royal Caribbean launched the biggest cruise ship in the world, the gargantuan Icon of the Seas, with a quarter of a million gross tonnage, more than 7,500 passengers and crew, 20 decks, an indoor waterpark and an actual park.

If these modern sea monsters, with their garish amusements, are an often unloved sign of the resurgence of cruises, then the Odyssey – roughly a 10th of the size – points to a different trend. It’s not about a leisure break so much as a lifestyle rethink. The governing principle seems to be that better than a home near the sea is one on it.

As Mikael Petterson, chief executive of Villa Vie Residences, said as the Odyssey finally pulled out from Belfast Lough: “From this moment forward, our ship is not just a vessel but a home.”

That home comes at a price of between $99,999 and $899,000 (£75,000-£685,000), depending on the size and comfort of the cabin, although only the mid-range are now available, with two-thirds of the accommodation already sold or rented. Ownership – which is contractually guaranteed for a minimum of 15 years (at least four circumnavigations) or, if longer, the operational life of the ship (it’s already 31 years old) – means that you can customise your cabin, come and go as you please, and also lease it out.

If this sounds like a radical development in ocean cruising, something like it has been tried before. Back in 2002 a cruise liner called the World was launched after a promotional campaign lasting several years that sold the idea of living full-time on a luxury liner to an upmarket clientele. They also had the choice of buying or renting, but the business was close to capsizing within a year of the ship ­setting sail. The model of wealthy long-term owners and short-stay guests proved to be unseaworthy.

As one owner put it at the time: “If you’re a hotel guest, you just can’t care for a place the same way you do when it’s your home.”

Well, sure, if you’re Ozzy Osbourne and you want to unwind by ripping a TV from the wall and chucking it in the sea. But most luxury hotel guests are not going to do anything more transgressive than leave a towel on the cabin floor.

The real issue, of course, was exclusivity. There’s a distinction among the very wealthy that’s known as the haves and the have-yachts. And the kinds of people who are rich but not necessarily in the super-yacht-owning class don’t want to share a residence with tourists, however well-behaved.

So the World relaunched in the style of a Manhattan-style co-op in which everyone has a share in the ownership and running of the vessel. Similarly owners were able to screen potential buyers, thus ensuring that there were no unwelcome types who might bring the tone of the neighbourhood down by sporting the wrong swimming trunks.

Twenty-two years on, “the world’s only residential community at sea”, as the World calls itself, is still making its way around the world.

Over that length of time it might appear the danger was not ­getting seasick but growing sick of the sea. But no one is permanently there.

“Most of our owners typically own, on average, for about seven years,” says a salesperson for the World, “although we do have some that have owned since the ship first started sailing.”

The ship’s itinerary is decided by a committee of residents, with stops every two or three days and no return to the original port of departure for at least three years.

In reality the World isn’t a home but a second home. Most residents stay around fourth months spread out across the year, with typically two months in the summer and another two around Christmas.

“We have a very high net worth community,” explains the salesperson. “The net worth requirement to own on the ship is $10m unencumbered. So for these residents, this is probably their second, third or fourth of multiple homes.”

The World was somewhere near Papua New Guinea on Thursday, heading towards Australia, but in a sense it could be anywhere, unencumbered by normal concerns. Because the World is an oyster filled with pearl-clad residents, a mobile yet enclosed society forever moving between one non-place and another.

It was the French anthropologist Marc Augé who made the distinction between places and non-places. A place empowers people’s identity; it’s somewhere that social groups form through shared cultural references. By contrast a non-place is a space of transience in which ­people remain anonymous. Augé cited motorways, hotels rooms, airports and shopping malls as examples.

To the narrowly socially defined residents of the World, the ports and people they visit must eventually merge into a series of indistinguishable backdrops: it’s Thursday, this must be Bora Bora.

Even so, two other ships recently hoped to follow in the World’s wake, and both were propelled, like the original, by waves of publicity. The first came from a company called Life at Sea. It promised a three-year cruise of 135 countries and 375 destinations, and marketed itself not just at the traditional clientele of senior citizens but also young digital nomads, who, thanks to first-rate internet arrangements, could work from anywhere on the high seas.

The package had everything except, it turned out, a ship, a minor detail that eventually scuppered the grandiose plans.

The first person to sign up for the aborted cruise was former flight attendant Meredith Shay, who was not alone in selling her home and most of her possessions to finance the trip. She paid $562,000 for a seventh floor cabin with a balcony. But Life at Sea was all at sea, and towards the end of last year had to admit that no one was going anywhere.

One of the people involved with Life at Sea was Mikael Petterson, who is now CEO of the operation behind the Odyssey. But his is not the only story around. There is also the Narrative. That’s the novel name of a liner commissioned by Storylines cruises which was slated to sail this year. However the Narrative, which will be powered by liquified natural gas, is yet to be to constructed and now won’t be ready until 2027.

Nonetheless two years ago stories began appearing of people buying into the notional ship. A couple from Los Angeles, Beth and Mark Hunter said that they bought a £1m two-bedroom apartment so their daughters, then 12 and 14, could see the world. By the time the liner leaves harbour in Croatia where it is being built, they’ll be 17 and 19 – ages when independence from parents is often a prerequisite for global travel.

Units on the ship are reported to range in price from $300,000 to $8m, though why someone who could afford $8m would want to share their communal space with 529 other cabins is one of those mysteries, like the Bermuda triangle and Atlantis, that the sea tends to throw up from time to time.

The appeal of cruises has always been a divisive subject – one person’s sumptuous dreamboat is another’s polluting prison ship. Perhaps, however, the underlying attraction of a home at sea is not to see the world but to be removed from it. With the planet heating up and wars breaking out, the temptation to turn to the pacific expanses of the sea is not hard to understand. At least until a storm brews, a pandemic hits or you really don’t like the people in the next door cabin.