Half a century on, Harris - now 77 and recently retired as the owner of a U.S.-based travel business - is on his seventh such voyage, having developed something of a taste for sea crossings between his birthplace in England and adopted home.

More than twice the size of the original "Queen Mary" - launched 1936, retired 1967, now a floating Los Angeles hotel - the modern "Queen Mary 2" has a very different feel from those early trans-Atlantic liners, perhaps closer to the modern cruise ships that ply the Caribbean and elsewhere, stopping at ports along the way.

The wooden deckchairs that line the promenade deck beneath the lifeboats may be the most potent physical reminder of what life was like aboard the QM2's predecessors. But the sense of separation from the outside world that comes with seven days at sea between Southampton and New York remains largely the same.

"I love it," Harris told Reuters four days into an August voyage. "You can't get phone calls, you get into a rhythm. It's a great feeling, even on a completely different ship."

After an annual world cruise to Australia between January and March, the Cunard-owned QM2 spends most of the rest of the year on the last scheduled transatlantic passenger schedule as what one crewmember called "the world's poshest ferry service".

Certainly, some aboard - including this reporter, paralysed from the shoulders down and headed to the United States for an assignment in Washington with a bulky electric wheelchair and some unpleasant memories from flying - are using her as just that.

But for the majority of the roughly 2600 passengers aboard, many on their second, third or fourth trip, the appeal is the voyage itself.

In their 20th-century heyday, the liners carried all levels of society, from great celebrities to those like Harris who scraped together all they had to share a cabin with bunk beds. Sea crossings gradually gave way to air travel as transatlantic services increased after World War Two.

Passengers today are often older, with an average age sometimes well above 50. But - particularly in the summer - there are also younger couples and families, as well as the occasional backpacker.

On almost every voyage, the ship hosts a reunion of anyone aboard who sailed on the previous "Queen" liners. A dozen or so passengers - sometimes more than 20 - share reminiscences of stormy passages, shipboard dalliances and slipping crewmembers money for tours of the most exclusive first-class dining areas.

Others recall when the original "Queen Mary" and sister "Queen Elizabeth" were used as troop ships during World War Two, running a gauntlet of German air attacks and U-boats.

"Is it an anachronistic way to cross the Atlantic?" says Chris Wells, the current captain. "Perhaps. But it has a romance that you simply don't get with air travel."

The cheapest cabins aboard - inside double rooms with no view - can retail for under £700 per head, while more luxurious, larger and better located twin level or multiroom cabins can cost several times that. The price includes all on-board food and entertainment but not alcohol.

Cunard still offers two separate upper classes with separate dining and socialising spaces. But even those in the cheapest cabins have waiter-served three-course meals and a dress code that for several nights includes black tie.

Crossings in both directions, Cunard officials say, are almost invariably fully booked - leading some to ponder whether a second ship might one day be added to the route.

GYM, LIBRARY, BALLROOM, WHALES

When the New York- and London-listed cruise giant Carnival Corp bought the ageing Cunard line in 1998, the British firm - founded in 1840 and later merged with White Star, owners of the ill-fated "Titanic" - was widely seen in terminal decline.

Its flagship, the much-loved "Queen Elizabeth 2" (QE2), was approaching retirement and there were doubts a transatlantic liner could survive in the modern era.

Carnival - which also operates a string of other major lines including P&O, Holland American and Costa, owner of the Costa Concordia which sank in January off Italy with the loss of 32 lives - thought differently.

Built in the French port of Cherbourg, the QM2 entered service in 2004 as the largest passenger ship ever built, accommodating some 2600 passengers and well over 1000 crew - although that record has since been surpassed by new vessels.

The ship boasts 15 bars and restaurants, five swimming pools, a casino, theatre and cinema/planetarium. A woodpanelled library overlooks the prow and open ocean, as does the spa and on-board gym. Daytime activities include lectures by historians, journalists and others, needlework sessions, wine tasting and watercolour classes.

For those who cannot bear to be disconnected, there is a sluggish - and pricey - satellite Internet connection. But for much of the day, many passengers seem content to simply read, stare at the ever-changing seascape or walk the promenade deck, each circuit 620 metres and three equalling just over a mile.

The occasional sight of a whale or dolphin prompts a periodic rush to the hand rails with smart phones and cameras.

Unlike with "Titanic", QM2's owners make no claims the ship is unsinkable - although nervous travellers can take comfort from the fact the ship carries more than enough lifeboats for all. On winter passages, she sails further south and keeps a close lookout to avoid the ice that sank her legendary predecessor in April 1912.

BUILT FOR TOUGH CONDITIONS

More recently launched Cunard sister ships "Queen Elizabeth" and "Queen Victoria" are of almost equivalent size and have the same black hull and white superstructure of historic liners. But while they tend to sail traditional cruise routes, QM2 is specifically designed for the tough North Atlantic.

The ship's deck plating is an inch thick - twice that of many conventional cruise ships - and the hull is streamlined to cut through the largest waves. Stabilising fins can also be deployed to reduce the movement of the ship.

While the great liners of the past would often tie up in the heart of Manhattan, QM2 is so large that she would block a significant part of the Hudson River.

Instead, the ship docks in nearby Brooklyn, towering some 14 stories above the quayside and passing under the Verrazano-Narrows suspension bridge with metres to spare.

Despite the earliness of the hour - around 5 a.m. - the decks and lookout points are almost invariably packed as the ship enters port, passing the Statue of Liberty like thousands before her.

For New York litigator Victor Stewart, 61, whose earliest memories include the multiple crossings with his parents aboard the original Queen Mary, some of the magic has been lost, and the on-board reunion can sometimes be a wistful affair.

"But sometimes, just sometimes, you come across something - even just a feeling - that takes you back to how it used to be," he said. "It's almost impossible to put your finger on, but it is definitely there." (Editing by Sonya Hepinstall)

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