Hands raised, the men wait. Their gloved fingers twitch, beads of sweat forming on their brows. The tension is palpable, like a scene from a Spaghetti Western. Except this is western Ireland and for spaghetti, read: oysters. Lots of oysters.

This is the Galway International Oyster and Seafood Festival and the men are champion oyster shuckers from all over the globe. They are taking part in the World Oyster Opening Championships 2011, the highlight of a three-day festival that's been hailed by The Sunday Times as one of the "12 greatest shows on earth".

As well as crate upon crate of bivalve molluscs, there are marching bands and street parades, vintage cars, Irish dancing, live cooking stations and a glamorous Oyster Pearl Festival Queen. Everything converges upon the harbour at a marquee the size of an aircraft hangar with a bar the length of an Airbus A380.

Galway is the perfect town for a celebration of this magnitude. It may be the third-largest city in the Republic of Ireland but it's regarded by many as the cultural capital. The annual Galway Arts Festival has played host to a glut of star names from Primal Scream to David Hockney and culminates in the notorious Macnas Festival Parade, a vibrant display of riotous street theatre. Then there's the Galway Races, immortalised in verse by WB Yeats. It's Ireland's longest horse race, with seven days of runners and riders, winners and losers.

Few cities would have the energy for it. But Galway is buzzing with life as a stroll down the paved lanes of the Latin Quarter confirms. Bars, cafés and restaurants spill out onto the street while tourists wander and buskers hum and rattle their tins for change.

Shop Street is the main thoroughfare where one of the city's best-preserved old buildings stands. An edifice of limestone with Irish Gothic carvings, Lynch's Castle dates back to the 1650s, a time when Galway was ruled by a group of merchant families known as ‘the tribes'. Their power eventually waned but their flags and coats of arms are still standing tall on Eyre Square, a city park once visited by John F Kennedy.

But history counts for nothing at the World Oyster Opening Championship - you're only as good as your last shuck. The first heat is about to begin. At the signal, the oyster openers drop their hands and start shucking. Jamming stumpy-but-sturdy blades into the flat shells, they prise open oyster after oyster as the stopwatch ticks. The action is frantic. Sweat drips, oyster juices splash and shell fragments fly everywhere. There are 30 oysters each to be opened, then each tray of oysters is judged for presentation, cleanliness, even blood. Oysters don't bleed but clumsy oyster openers often do.

As he waits for his turn, Finland's Martin Söderstrom steadies his nerves with a pint of the black stuff. "This is my first one of the day," he says with a smile. "And it will be the only one - before the competition!" Söderstrom is a buyer for a fish company and this is his first time competing in Galway.

He lines up alongside some titans of the oyster shucking world - Hasse Johannesson of Sweden, who recently opened 15 oysters in 45 seconds; Belgian Xavier Caille, a previous world champion who goes by the nickname ‘X-Factor'; and Ireland's own master shucker Michael Moran.

There's an art to opening an oyster, especially the native oysters of Galway Bay. Unlike the deep, tear-drop shaped Pacific or rock oysters, native oysters are flat and stubborn. You have to attack them at the hinge, use all your strength to lever them open without slipping and stabbing yourself in the stomach. It's all about practice.

Once you've got it mastered, the rewards are worth it. These oysters are rarer than the ubiquitous rock oyster and only in season when there's an ‘r' in the month. They are usually harvested at around four to five years old, whereas rock oysters rarely see their second birthday. Filtering up to 11 litres of fresh Irish sea water an hour, they're bursting with minerals. The result is a bold ocean flavour considered by many to be the finest in the world.

Diarmuid Kelly is the official supplier to the festival. He's also a supplier to a host of restaurants around Europe and culinary luminaries like Rick Stein and Delia Smith. The family business that he helps run has been present at the festival since the 1950s. The festival began in 1954 when a local hotelier devised a plan to extend the holiday season into autumn. "This is a family business, we were brought up with it," Kelly says. "My father started it, my mother joined him and they grew it along into a nice export business." He points to a young lad of about 12 years old, apron on, knife in hand, busily shucking shellfish like a pro. "My own son Colin is here. This is his first year so he's practising, opening away..."

It would be bad manners not to try one, or 12. Galway oysters have a strong and distinctive flavour that few can match. A metallic punch with hints of iodine. The flesh is creamy beige, paunchy and tender - a silky mouthful of the sea, which Kelly puts down to the unique location of Galway Bay.

Sheltered between the clean, wild hillscape of Connemara to the north and the Burren Mountains to the south, the sea water mixes with fresh water to great effect. The oysters tell the story of a magical rugged landscape.

One or two minor wonders have been performed at the oyster opening championships. The pressure and expectation has been building all afternoon but a victor emerges among the shell chipings. With a highly creditable score of 30 oysters in two minutes 40 seconds, the winner is ‘X-factor' Caille - a rangy, silver-haired shucker with the supple wrist action of a pinball wizard.

"The oysters in Ireland are the best quality. And flat. It calls for a different technique," says Caille, almost breathless after his win. "I love opening flat oysters, it's my passion. I am very much a specialist of opening flat oysters."

And with that, the world oyster opening champion disappears into a crowd of moshing revellers, as the live band cranks up the volume and starts belting out some Elvis. The dance floor fills, drinks flow and oysters are guzzled into the night. This is how things roll in Galway.

Where to stay

Hotel Meyrick
If they're famous and they visited Galway, chances are they stayed here. Bing Crosby, Fred Astaire, Jack Nicholson, John Wayne, Paul Newman, the writer Brendan Behan and footballers George Best and Kenny Dalglish are just a few of the stars to have enjoyed the Meyrick. Since 1852 it's been the grandest hotel in town, and it's where the Galway Oyster Festival was conceived and first hosted, nearly 60 years ago.
Eyre Square, Galway City, +353 91 564 041
www.hotelmeyrick.ie

The Ardilaun Hotel
If the energy of the city is all too much, the Ardilaun offers a relaxing haven just outside the centre of town. Set in landscaped gardens, the hotel is steeped in history. It was built around 1840 as a home for a family of distillers and opened as a hotel on St Patrick's day in 1962. Now it's got bars, restaurants, a gym and swimming pool and some of the cosiest rooms in Galway.
Taylor's Hill, Galway City, +353 91 521 433
www.theardilaunhotel.ie

Where to eat

Moran's Oyster Cottage
It doesn't get any more quaint than this. Dating back to the 1790s, this thatched-roof pub serves some of the finest oysters and seafood in Ireland. It's situated close to the Galway Bay oyster beds that yield the fabulous native oysters, and it pulls a smooth Guinness to wet your whistle with. It's been run by the Moran family right from the beginning, and Michael Moran is the current Irish oyster opening champion.
The Weir, Kilcolgan, County Galway, +353 91 796 113
 www.moransoystercottage.com

McDonagh's
Michael Kelly's native oysters are one of the highlights at this Galway institution. But why stop at oysters? McDonagh's is renowned for its excellent fish and seafood, from its wild Clarinbridge mussels cooked in a Thai sauce, the seared scallops with black pudding or the traditional fish, chips and mushy peas.
Quay Street, Galway City, +353 91 565 001
www.mcdonaghs.net

Paddy Burke's
Just 15 minutes drive south of Galway City, Clarinbridge has an oyster festival all of its own (also in September) and Paddy Burke's is right at the heart of it. The local native oysters feature prominently, as you'd imagine, but there's meat and fish dishes galore at this traditional inn.
Clarinbridge, County Galway, +353 91 796 226
www.paddyburkesgalway.com