Architecture: When the boat comes in

They like their boats on Jersey. And cafes. But a pounds 500,000 cafe resembling an upturned hull is harder to disgest. Jay Merrick charts the island's brush with the future

A small cell of hardy radicals in Jersey, the dollop of offshore granite, lucre and Methodism, has cocked a calculated snook at the island's conservative heritage with a startling piece of architecture which the residents didn't want.

This rude paragon is 33 metres long and shaped like a tubby fish trying to mutate into an upturned wooden boat. It is called La Fregate, sits just above the beach opposite the Grand Hotel in St Helier and cost pounds 500,000. It's a caff.

Some caff. Based on a hastily painted conceptual squiggle by Will Alsop of Alsop & Stormer, the fashionable London practice responsible for the widely acclaimed Le Grand Bleu government complex in Marseilles, La Fregate has put Jersey for the first time on the international design map; it is one of a handful of projects being exhibited at the current Sao Paulo Biennale along with much larger-scale work by big-hitters, including Terry Farrell and Nicholas Grimshaw.

La Fregate's sleek, wind-tunnel-tested form is the blue touch paper for a pounds 120-million redevelopment project by the Waterfront Enterprise Board. Its structure, an in-your-face essay in raw form and ad hoc innovation in its details, has set a crucial precedent in St Helier's bid to blast the island's tourist industry into the 21st century.

Crucial and ruthless. Sixty yards away, just beyond the German bunker converted into public loos, stands La Fregate's flaky predecessor, a boarded up throwback called the West Park Cafe. The nondescript cream and scab- red chalet is scaled with Wall's ice-cream boards and barnacled to a past echoing with the fatal drone of the Ronettes and thronged with ghostly leather boys

Derek Mason, whose local architectural practice helped to kick-start the project, can barely contain himself. "So what do you think of it?" he asked. He is sitting - trimly attired, softly spoken, Rotary badged - in the sleek white interior of La Fregate, with his colleague, John Leveridge. But his question poses a problem. Being in La Fregate is not necessarily an intellectual exercise; more a gut experience in which Irish nut latte dusted with nutmeg (not quite the thing for a 1950s Cafe Bongo, admittedly) may be sipped in the airy clasp of a precisely eviscerated whale; its gubbins having been removed through the wide, double-glazed belly slip which runs the length of its undulant seven-metre-high ridge.

It's 2pm and the light from the west has randomly blocked the bulging wall of the "pod" that contains the kitchen, storeroom and office with luscious rectangles of red, blue and yellow. The jutting window frame reveals - in utile, a tropical hardwood, coated with glass-reinforced plastic - add to the colourful little twist on Le Corbusier's church at Ronchamps and the paint jobs on the amphibian vehicles that cart sightseers out to Elizabeth Castle in St Aubin's Bay.

But corn on the Corb is not the issue here, because the key to La Fregate's design is not the usual comforting braid of architecutural "context" and "vocabulary" items; the building is more radical than that: out goes Moby diction, and in comes what Mason calls pure design.

"This is beyond the post-modern," he insists. "This is purposeful, wilful shape-making at the top of the agenda. Function and materials are subservient to shape. This is the end of the 20th century talking!"

It wasn't a quiet revolution, either. According to Mason, who delivered the final design working with Leveridge and Alsop & Stormer's Andy McFee, progress was tortuous; the project nearly died half a dozen times, storm-tossed by Jersey's essentially feudal approach to public processes, an "impotent" planning department and a local paper fanning rumours that the building leaked, or was losing its roof, or settling at one end. Mason expected nothing less: "Good things have to have that air of danger and crisis. They don't just happen."

Even the ultimately adventurous enterprise board - Mason is a member - took some convincing. After Alsop turned up to galvanise them "they still wanted a repro pastiche interior", according to Mason. "Why weren't there wooden props? Why weren't there sailors, and why can't the top be sailcloth?" When the project started on site in January, he and Alsop sat on a piece of plywood and looked out to sea, wondering if the building would work.

There was good reason for their concern, for the truth is that La Fregate's detailed design was done on the hoof. The only aspect that was a cert before work started was the grid of 12 curving steel ribs and timber infills that would carry the whole thing.

The tricky stuff, such as the potential sieve at the junction of the ridge glazing and the wind-accelerating cedar outer layer, was solved as the project progressed. So, too, was the design of the mechanism for opening and closing the cafe's 1959 Mercedes 300SL-styled gull-wing doors; it's amazing what can be done with Ford van spare parts. Even the cedar cladding posed a severe challenge to local boatbuilders, Dave Matthews and Paul Haslam: the apparent depth of the boards had to appear identical, regardless of the slope or horizontal curve of the building; it was fiendishly difficult.

The only thing that Mason knew for sure was that La Fregate, as a landmark building, had to be very special indeed. His early research was extensive. He travelled, studying the Notting Hill flower stall by Piers Gough, the bookshop in Venice by James Stirling; and Alsop & Stormer's Cardiff Bay centre.

Alsop, an old friend, was called in "to give us a good shake - and I rejected his original proposal. And that afternoon he came up with this little painted fish, a beached fish with a boat section and gull wings. Absolute brilliance. It was all there from the start."

But La Fregate, despite its architectural importance, will remain controversial in a town where the height of cool is The Babylon, a newly refurbished cafe-bar and club, which, as Mason pointed out over a mayonnaise-drooling, quintuple-decker chicken sandwich on a stick, "is the place to be seen"; or smeared, perhaps.

The Babylon's pick-and-mix decor sets the popular benchmark: candy-twist brick pillars with classical wooden pillars separating Gothic-shaped mirrors, chunks of "Greek" frieze and a fireplace set into the bellowing mouth of a huge, Learish face with a supernova of hair: William Golding in agony from a copy of the Naked Lunch jammed up his backside. The white-wine- and-sodas are thunked down, black straws and swizzle sticks twitching like the legs of drowning spiders. The Babylon Five ("five different vodkas for just pounds 6") suddenly seems like a logical necessity.

By contrast, La Fregate's only obvious concession to popular taste is the tiny souvenir shop at one end, half hidden by the bulge of the internal pod. There's a gobstopper dispenser, drink mats, La Fregate teddies, copies of Victor Hugo's The Toilers of the Sea, videos of The Wreck of the Stella and a tray-full of plastic eyes.

The cabbie, a Tommy Trinderish character, eyeballed La Fregate as we swept past on the way to the airport. I asked him what he thought of it. "Not much," he said. "If they had to build a new one, don't see why they couldn't have used Jersey granite."

And then, at the airport, an interesting find in the modest exhibition relating to its 50th anniversary; a blow-up page from the local rag on 20 October, 1917. The story, based on a lecture to the St Helier Church Literary Society by Miss Gertrude Bacon, is headed: "Flying machines in peace and war".

"How very much like a bird is the modern aeroplane," she told the stolid burghers. The reporter also noted that, "Miss Bacon had looped the loop twice over and felt it a perfectly safe and simple proceeding."

Eighty years on, how very like a fish is the modern cafe; Mason, Alsop and the development board have looped the loop, architecturally. Perhaps the islanders will find that it is a safe and simple proceeding after all. The cabbie said he'd give it a go