The air is cold, crisp and clean. It smells of salt and champagne. Coiffed women stroll by with coiffed dogs. My hot chocolate tastes like molten Galaxy. I smooth my skirt (satin-effect, Warehouse, £35) and look nervously around for the Deauville style police.

The beach is flawless down to the sea, nothing on it but one small boy playing neatly in a sailor suit. Shop windows sparkle. The mixed cries of seagulls and wood pigeons are interrupted only by the occasional soft whump of Rolls-Royce wheel on cobble. Why aren't English seaside resorts like this off-season?

Don't get me wrong - I'm never happier than when skipping around Margate in July. My soul sings at the very thought of a hot day in Blackpool. But a cold day? (Shiver.)

You won't find old chip wrappers and fag butts on the streets of Deauville. You won't find locked-up amusement arcades, lonely in the off-season gloom. You won't see fat kids with implicitly violent haircuts, swaggering along as if they own the street, legs apart, mouths hanging dumbly open, texting on their mobile phones. The air doesn't reek of piss and alcopops. Nobody has stopped caring about the town just because the tourists won't be back til summer.

Technically, I wasn't a tourist in Deauville myself. I went there for the French leg of the European Poker Tour. I chose to play this tournament over Copenhagen and Barcelona because I have always had a soft spot for Deauville, the kitsch jewel of the Normandy coast. Its prettiness has not dimmed since the 1920s, when it was the resort du choix for duchesses, debutantes and devilish gigolos with slicked hair and gold cigarette cases. I packed my suitcase with period novels and made a point of reading them on route, in the buffet car of the rattling train.

In Agatha Christie's Evil Under the Sun, a murder suspect is immediately wary of Hercule Poirot because there is no reason for the natty well-dressed fellow to be holidaying at the English seaside. 'A man like you,' mutters the villain suspiciously, 'should be at Deauville or Le Touquet.'

Ian Fleming sent James Bond to Deauville in his very first story, Casino Royale. Every man is James Bond in this town, and every woman is a Bond girl. You can barely move for oysters and gambling. The racecourse is legendary and the seafront is dominated by a white-pillared casino. For the picky punter, it is but seven minutes' walk to an equally beautiful casino in Trouville, the twin town next door where Napoleon and Alexandre Dumas took their holidays.

I felt so 1920s-literary on these cobbled streets, I was rather sorry not to have had a moustache. I could have waxed it in the bathroom mirror and twirled it in the casino.

Last time I was here, there was a jazz festival. I think the reason Deauville stays so clean and pretty is that there is always some kind of festival or exhibition going on. British resorts seem to shut down in September when Bobby Davro waves goodbye - until the next June, locals might as well chuck their chip wrappers on the street. Nobody's coming.

But Deauville has a constant air of visitors being due. It is always tidy, shining and ready. The racecourse attracts punters from all over Europe. The autumn film festival is the toast of the world. Wooden gates along the seafront boardwalk are painted with names of the film stars who have visited, from Matt Damon to Joan Fontaine. (Also, oddly, Buzz Aldrin. What an actor, that Buzz. I loved him in Chicago.)

This year, sandwiched between the flower festival and the Calvados festival, came the poker festival. I would normally attend one of these pretending I was Steve McQueen, but this time my head was too full of Agatha Christie. I couldn't be McQueen in evening dress. I had been invited to play by Pokerstars.com, the website that sponsors the European Poker Tour. Many of my opponents had won their Deauville trips on the site: winning themed holidays in exotic locations is the hottest trend in internet poker.

So Deauville was thronged with people who would never have been there otherwise. One young Texan told me that he found the town's neat little flower beds, stone-cellared wine museum and 'wooden architecture' so romantic that he had proposed to his girlfriend immediately. If he's lucky, he'll win another tournament online, net a trip to the Caribbean, and that's the honeymoon sorted.

But gamblers love a luxury lifestyle, and we were happy to throw our own euros around in Deauville's restaurants and bars. You have to tip your hat to the French casino visionaries who persuaded Pokerstars to hold a tournament in this town: I lost enough money at blackjack to buy them a new set of chandeliers.

Luckily, I was at least occasionally attracted outside. Deauville is a curious-looking place, strangely alpine for a seaside resort. It's all funny little gingerbread houses with wooden beams and pointy roofs. The cobbled roads are painted in cute scallop shapes and lined by black-and-white checkerboard pavements. I scoured the back streets in vain for one ill-kept house: even the town's outskirts are a vision of wooden-slatted, pastel-painted perfection. It's very chocolate-box, but stunning if you like that sort of thing. And why wouldn't you? It would be like not liking kittens.

On my first walk around town, I encountered so many perfect French characters that I began to suspect I was in an episode of The Truman Show . An invisible director must have shouted: 'OK, and ... cue the cycling man with the baguette! Send in the old lady with the lipstick, fur coat and poodle!'

I had intended to go shopping, but I couldn't afford anything. Instead, I stopped to have lunch alone by the sea, which I thought was terribly elegant and grown-up. Or would have been, if I hadn't ordered ham sandwiches and hot chocolate. (It's not like they didn't have oysters on the menu; everywhere in Deauville has oysters on the menu.)

I did a lot of dressing up. Something about the place makes you want to wear long skirts and jewellery. I put on full make-up every morning, and spritzes of cologne. It was like one long fancy-dress party, and I was attending as a 1920s heiress. Another reason to see Deauville in cool weather is that one senses it would be déclassé to wear a bikini round here anyway. In the height of summer, I shouldn't be surprised if people are still strolling on the beach in lounge suits and silk dresses.

If you want to leave town, it is an easy drive to the pretty fishing port of Honfleur, the Basilica of Lisieux, the D-Day beaches or the rolling Bocage countryside. But I didn't. The Deauville casino had a giant poker tournament upstairs and a camp, jetset nightclub downstairs - I had no reason to spend my money elsewhere. Like I said: they're not fools, these people.

Factfile

P & O Ferries (0870 520 2020; www.poferries.com) has a crossing between Portsmouth and Le Havre from £75 each way for a car and up to four people.

The closest big airport to Deauville is Paris Charles de Gaulle, from where you can take a train. EasyJet (0871 750 0100; www.easyjet.com) has flights from Luton from around £40 return.

The Normandy Barrière (020 7629 5003; www.lucienbarriere.com) hotel is an elegant black and white building with chandeliers, spa and fitness centre and a restaurant especially for children. A double costs from £175 per night B&B.