Mile after mile of damp, deserted beach, empty caravans on Canvey Island, eating fish and chips parked up on the front Photographer Martin Salter documents the British seaside resort in winter.
Frank wants to see where the River Thames "runs into the ocean". He has come all the way from California - Sacramento to be exact, as his sweatshirt reveals - and it seems unkind to disillusion him with talk of the pond that is the North Sea. He is beginning to sense something is wrong, though, as our train meanders through the various coastal towns of the north coast of Kent. "Is that a beach?" he asks, screwing up his chubby nose at the sight of a mud flat just past Faversham. Next to some of California's best, as featured in Baywatch and The Rockford Files, I can see that it doesn't quite pass muster. Pamela Anderson would need galoshes and a woolly before playing volleyball on this shoreline.

I try the quaint English charm angle on Frank by pointing out some beach huts the other side of Birchington-on-Sea and describing the time-honoured ritual of getting out the deck-chairs and brewing up on the Primus in the face of a force-nine gale. "But what is there to look at?" he says as he gestures despairingly at the flat grey waters. I'm glad I'm not going all the way to Ramsgate with him.

The sun breaks through the clouds as I get off at Broadstairs and wave goodbye through the train

window. Looking up at the sky, I suddenly feel optimistic. After all Charles Dickens, Broadstairs' most famous ex-resident, wrote that this resort beat "all watering-places into what the Americans call `sky-blue fits'". Perhaps I should have mentioned Dickens's words to Frank. He might have explained what a sky-blue fit was, but then there was every chance he would have followed me. And despite the sun, I know that a January afternoon in Broadstairs is unlikely to turn him on to the British seaside experience.

Nature has been kind to Broadstairs. If the sea is the stage, its beach - chalk cliffs that rise up steeply to the Esplanade - forms a Roman amphitheatre. The elaborate iron balconies on even the most humble ice-cream parlour, and the vast Victorian Gothic hotel block on the headland, suggest that once this was quite a place.

But time has taken away what nature has given. The buildings are crumbling. It is more than a question of out-of-season maintenance work waiting for a dry day. At the sea-facing Albion Hotel, according to a 1902 guide the best place to stay in Kent, the pinky-orange paintwork is pock-marked and the window timbers rotten. Even the lick of emulsion being applied to the Blue Anchor, a treasure trove of coloured balls in fishing nets and souvenir tea-towels, cannot disguise the feel of a town in a decline as steep as the steps leading down to the beach.

But you can't judge an English seaside town on an out-of-season afternoon. They're meant to be deserted and depressing. And, sure enough, the only vehicle in the sea-front car-park is a Ford Escort in which a couple is eating fish and chips. Silent and seemingly a little sad, they are looking out emptily on the emptiness beyond.

There is nothing else to do here but look at the sea. What few attractions Broadstairs can boast are closed for the winter. Up on the hill, the Dickens Museum - which also offers maritime and smuggling exhibits in an odd seaside cocktail - announces proudly that it is open daily, but the gate is padlocked. A lone poster on the tourist information board offers a ray of hope - a very special night with Isla St Clair, two decades on from her supporting role on Larry Grayson's Generation Game, at nearby Ramsgate in February. Unlike Broadstairs she doesn't appear to have aged at all.

There is something half-hearted about this place. Its belief in its gentility - unlike its tackier neighbours, Ramsgate and Margate - means that the thrills and spills usually available all the year round in seaside towns are absent. The only amusement arcade is tucked up a side-street and the woman behind the counter looks affronted when I go in. Even the beach, pleasantly golden even in the bright January light, is so ringed with concrete walls, concrete steps and concrete lavatory blocks that it is more like a footpath than the edge of the land.

That just leaves the sea. Out on the small jetty that has replaced an earlier pier, I sit down in the only shelter on offer, a high-roofed, dank Scandinavian-looking thing that might have come out of an Ikea catalogue. I'm the only person there. It is so designed that none of the winter sun can get in. After 10 minutes of shivering in its recesses, it's tempting to try and squeeze into the Ford Escort, but it now has steamed-up windows.

Up on the prom, the York Gate Cafe and Milk Bar is open, but the lights are off and the door is most reluctant to open. "It's the wet," says the owner. "It ruins everything." I pick up the menu. "We're not doing food today."

But there are, on closer examination, signs of life in this out-of-season landscape. Like the brand-new block of Barratt flats next to the Victorian headland hotel. Broadstairs may for nine-tenths of the year have all but died as a seaside town, but it has developed another on- going life as a retirement place and even as a commuter town for those Londoners willing to spend three hours a day on the train in order to come home to a breath of sea air.

And for those of a melancholy or solitary disposition, Broadstairs clearly has an appeal. The local cinema - reputedly the smallest in England, but open all the year round - is showing Meryl Streep's Dancing at the Lunghasa. In Margate it would be a Disney classic, or something upbeat, but here you can escape the gloom of Broadstairs for an hour or two and be transported to the gloom of Co Donegal.

"This is the best time of year," a young, balding man behind the counter in Albion Books later tells me when in desperation I insist he talks to me. "You can have the beach to yourself. There is space. I grew up here and then went away, but I decided to come back for a while and I'm glad I did. It's not a bad place to be."

Such an endorsement is hardly enough to sustain a seaside town when the visitors have gone away. The residents in the neat bungalows and semi-detached villas that stretch up the hill to the station can't quite keep this place going from October to May. They seem to be living a half-life, which when added to the remaining half of Broadstairs' seaside past somehow doesn't quite make a whole.

Dickens's sound-bite referred to Broadstairs as a watering-place and that was its origin and that of the vast majority of Britain's seaside towns. Doctors in the 18th and 19th century believed that seawater had special powers to improve your health, whether you swam in it, sat in it, washed in it, breathed it in, or drank it - especially in the morning.

Sea air was even said to reinvigorate sexual appetites - though this fact was whispered behind gloved hands - and a glass or two of the North Sea, the Channel, or the Irish Sea was, according to the manuals of the day, "sufficient in grown persons to give them three or four sharp stools".

Seaside Watering Places, a guide book which for a florin told turn-of- the-century keep-fit fanatics which resort to visit, epitomises the heyday of these health pilgrimages to the coast. Each entry includes key indicators of that town's life-enhancing powers and addresses of such holiday goods providers as makers of surgical trusses. Most resorts are judged not by hours of sunshine but for how few corpses they generate. Great Yarmouth does well at 22 per 1,000 per year. There are other criteria. Burnham on the Bristol Channel is, for no precise reason, "particularly beneficial to persons recovering from fever or other lowering complaints", while Seascale in Cumberland had waters with special healing powers for "asthma, diabetes, goitre, debility, dyspepsia and insomnia".

Broadstairs' near neighbour Margate once housed the Royal Sea-Bathing Infirmary on its western cliffs. Today the idea that a dip in the Thames estuary - or, better still, a couple of pints of it - would make you feel better is about as laughable as lying under a purple pyramid. And that, in short, has been the problem that most British seaside resorts have struggled with throughout the 20th century. Once they had lost their role as year-round hospitals or healing shrines, they turned their minds to pleasure. But it is, for the most part, a climate-driven option, and hence while they experienced the highs of the summer, they also condemned themselves to a long winter hibernation.

There are, of course, January-to-December pleasure resorts like Blackpool. But it has never tried to appeal to the health-conscious. Its tower, three piers and marine promenade were built in Victorian times for fun. Bournemouth and Brighton quickly tapped the same vein when their own health market declined.

But providing enough amusements that are climate-proof is a costly business, beyond the reach and often the imagination of the second-division resorts. Unless they have been lucky enough to attract a Butlins or Pontins, then they have been left in the summer months with the overspill from the premiership teams. Come winter, there is no reason for the fun-lovers to go there and no money to be made out of solitary souls standing on a jetty staring out to sea. Some of the places featured in the 1902 guide subsequently fell into such a deep winter slumber that today they scarcely wake up come the spring. Who now goes for a day on the coast to Hoylake on the Wirral or Shoreham-by-Sea with its half-demolished power station?

Yet for all the prophesies of their demise in the face of overseas package tours, the seaside resorts keep struggling on. Nearly four out of 10 domestic holidays are still taken at the coast in an industry worth pounds 4.8 billion last year. The big players - Butlins in particular - continue to invest heavily in the extremities of this floating island. It is as if we cannot give up the Victorian dream that heading for the edge of the land will somehow rejuvenate us, but we follow that dream in a different way from our parents and grandparents.

In the 1960s and 1970s we went on holiday every year without fail for two weeks to the seaside. Newquay, Tenby, Saundersfoot, Barmouth, Anglesey, Filey, Camber Sands, Criccieth, each one part of a collective memory of the struggle to fit the deckchairs in the boot, sitting between my parents on the middle of the front bench seat in our Ford Zephyr, Cherryade and crisps in the pub car park if we stopped for a drink, hotel menus, slot machines if it rained, my father wearing a big white baggy jumper, my mother, a championship swimmer in her youth, plunging headlong into the waves in a largely unsuccessful effort to encourage us to follow.

Mine was probably the last generation to enjoy this annual and reassuringly repetitive ritual at the British seaside. After a fortnight in August, it never occurred to my parents to take us again. Yet now, where in the summer I take my own child to beaches on the continent, I find myself out-of- season gravitating to the edge of our own land mass.

It may be a warming winter nip of nostalgia for an old British tradition of candy-floss, Union Jacks and the delusion, when standing on a rusting pier, that Britannia still rules the waves. Or perhaps just an attempt to link the generation below me with the one above me. Then again it may just be the space. When short days and long nights make the city seem oppressive and black, the beaches of the flat north Norfolk coast offer spectacular horizons where you can glimpse that the earth is truly round