Peter Ross at large: Viking-swilling raiders find their shopping Valhalla

The Norröna's orange lifeboats stand out like Dale Winton in the snow

ON A bitter winter morning in Edinburgh, a pale young man in a neat black suit is striding across North Bridge with a determined look in his eye and a golden can of Viking lager clutched in his left hand. He takes fortifying swigs and pulls along behind him a large black travel case. It's empty but won't be for long.

This man is one of 860 Faroe Islanders who have sailed to Edinburgh to spend one day Christmas shopping. They are inverse Santas, travelling from the frozen north, intent on taking a sackful home. Naughty? Nice? None of that matters. Whoever is willing to endure the 25-hour crossing from the capital Tórshavn can return with as many goodies as they can carry.

The Islanders have travelled here on the Norröna cruise liner. I had worried I wouldn't be able to spot her down at Leith docks, but she's impossible to miss. Huge and gleaming white, more iceberg than ship, her orange lifeboats stand out like Dale Winton in the snow.

At half-eight in the morning, the Islanders are getting an odd wake-up call – a piper on the quayside, giving 'Scotland The Brave' laldy. In truth, though, most of them are awake already, tucking into bacon and eggs. A hardy few have been up all night, drinking in the Naust bar. On the stairs, a group of twentysomething guys glug bottles of Smirnoff Ice; one has blood dripping from a bandaged hand. This isn't just a shopping trip, it's a floating party.

Not that I can blame people for drinking. The Faroe Islands lie between Scotland and Iceland in waters known for their treacherous currents. The waves can be awful. There's a film on YouTube of Norröna's bar stools rolling and tipping in a storm, one passenger skiting across the room, the foam of his lager sloshing out.

It's 9am and time for the Islanders to leave for the city centre. Coaches shuttle them back and forth all day. Ushered by the purser Berghild Jacobsen, I join the first coach load, which is about 98% female, and chat with some of the women on board, 99% of whom are called Ingrid.

"I've come to Edinburgh because it's cheaper," says Ingrid Hansen, 21. "It's very expensive in the Faroe Islands. And there's more choice here. A couple of friends of mine were sea-sick, but it's worth it."

A pint of milk costs the equivalent of £2, apparently, so our cheaper cost of living, plus the weak pound, means that the Islanders are well placed to find bargains. They have somehow avoided the credit crunch, and are even involved in bailing out the Icelandic government to the tune of 300m Danish kroner.

There are a few gasps from the left-hand side of the bus as everyone catches sight of the Old Town for the first time. The bus stops outside Old Calton Cemetery and we all get off. The Islanders, en masse, are quite a sight. You can tell them by their great love of decorative knitwear and by the fact that almost everyone is carrying a large suitcase to be filled, in short order, with booty. There's also a high standard of masculine and feminine beauty. An equivalent coach party of Scots turning up in Tórshavn would not be so aesthetically pleasing.

I get talking to the Olsen family – Olaf, Helena and Johnny (a girl with bright red hair) – who range in age from 16 to 25, and look like movie stars. Olaf has a camera slung round his neck. "I want to visit the Hard Rock Cafe," he says. "I am thinking of visiting all of them in the world."

The rest of the Islanders head directly for Princes Street and for their Valhalla – H&M. There is no H&M in the Faroe Islands, the closest is in Denmark, so this is the number one destination of the trip. The women more or less sprint over the racks and starting choosing things to buy. You have to be single-minded and decisive. The Norröna is going to set sail for home at 8pm, and everyone has to be back on board by seven, so there can be no loitering, or the Norse equivalent, umlautering, on this trip.

In H&M, Kim Petersèn, 44, is buying a Spider-Man tie as a stocking-filler for one of her sons. "I'm going to do all the Christmas shopping in Edinburgh and then I can relax for the whole of December," she says.

Downstairs, Jón Joensen, 24, is mooching by the Argyll sweaters. "I'm here with my girlfriend. It was her idea to come." Has he bought anything nice? "Oh, I'm not buying anything. I'm just looking." A long way to come for window-shopping, surely? "Yes," he replies with a glint in his eye that may not be unconnected with the fact that upstairs, right now, his girlfriend is buying purple and silver lingerie.

In a nearby shop, the Islanders are stocking up on Nessie mousemats and postcards of Highland cows. In the Jenners food hall they examine, in mystification and dawning horror, Stornoway Black Pudding. In Sports World in the St James Centre, women are bulk-buying Liverpool and Man Utd strips and hold-alls to put them in. Elsamaria Fidaberg is eyeing up an England football top for her boy. I tell her that's like me going to the Faroes and buying the Denmark strip. "I'm sure he'd like this," I say, pointing to the Scotland strip. She doesn't look convinced. I mention George Burley and she looks less convinced.

Back at the terminal, the security who X-ray the shopping bags, have never seen the like. "Get along to Asda and see them," says a man in a hi-vis jacket. "They're emptying the place. There's a guy just come back with four frozen turkeys, two under each arm. He says he's going back for more."

"They've bought all the Roses in Asda," says his colleague, shrill with incredulity, "and moved on to Quality Street."

I spot a family so laden with toys that they're using a metal wagon to get them on the ship. "You can't get High School Musical things at home," Ása Dam explains. By 8pm they're gone, nothing but packed cash registers to show that they were ever here. Well, that and a few cans of Viking lager crushed on Edinburgh's historic cobbles.