In the restaurants, in the pubs, on the beach: something fishy is going on in Whitstable. Daniel Synge tests the water
It was the Romans who first began dredging oysters from the sea beyond a shingly stretch of the north Kent coast. Oysters used to flourish here: during the oyster boom in the 1890s, up to 100 fishing boats were farming 60 million of them a year.

Today the Whitstable oyster rush is just a sepia memory. But you can sit facing the murky sea at low tide in a restaurant which was once the old Victorian oyster warehouse and order a dozen native oysters, washing them down with a bottle of chilled Chardonnay. As you swallow the slimy molluscs, it may cross your mind that this small harbour town appears to be frozen in time like a scene in a Hammer Horror film with Peter Cushing, the retiring film star who made Whitstable his home.

Along the high street past The Playhouse theatre, where the town's amateur dramatic society rehearse Mrs Worthington's Daughters, the small, family- run shops are about to close, as is usual on a Wednesday afternoon. It seems a pity to miss out on the checked bathing trunks and Famous Five sandals in the window of Hatchards, the hosiers and outfitters, or the humbugs and toffees sold in jars from a Dickensian confectionery shop, but there are bigger fish to fry in one of the few working harbours left on this coast.

The giant tuna, lobster and "fresh salmon for pounds 1" look good enough to take home, while cockles and whelks are sold in crates below the tall wooden fishermen's huts. Coach parties and day trippers jostle for the bargains but almost half the day's catch is whisked up the M2 to Billingsgate market in London.

On the other side of the harbour past the asphalt processing plant, ostrea edulis can be appreciated in finer detail at the Oyster and Fishery Exhibition. Fish bar mainstays plaice, skate and sea bass can be seen swimming in pools in the marine environment room. Showing us the inside of a storage shed where hundreds of oyster shells are purified in saltwater baths for at least 42 hours, our museum guide confirms what seasoned diners will remind you, that traditionally native oysters should be shunned in any month without a letter "r" in them (and never mind the fact that Whitstable's oyster festival takes place in July). What's more, they enjoy rhythmical hermaphroditism - the scandalous ability to change sex repeatedly throughout their lives.

We had ordered the rock variety back in the restaurant. These originate from Scotland or Ireland but are cultivated nearby on beds lying in the marshy waters beyond Seasalter, where there's an abundance of the algae and nutrients so essential to oyster farming. More good news for oyster lovers concerns their alleged erotogenic qualities. Due to their high zinc quotient, they really do help us to retain sexual maturity, an above- average brain and healthy skin.

Vaulting over the groynes or strolling past the small fishing boats, you may be surprised by the incoming tide. For the local windsurfers and jet-skiers it is the signal to zip up their wetsuits and spray surf around the harbour.

As the pinkish sun disappears over the estuary, we sit outside the Old Neptune with Guinness and potted clams. In Victorian times it was said that you could drink in a different pub every week of the year, never visiting the same one twice. This pub is noted for its old juke-box, crammed with classic rock, and for being so close to the water that the barstaff should be issued with masks and snorkels.

If you choose to loiter after dark, don't expect the "kiss me quick" vigour of Whitstable's more rumbustious neighbour Margate, but you could see a film in the cinema, housed in a former fishermen's meeting room above the Whitstable Oyster Fishery Company restaurant. The manager here can rent you one of four former fishing huts on Reeves Beach. It's more than tempting to have another drink at the restaurant, order some more oysters and then make for your hut where you let the sound of Whitstable's few remaining fishermen wake you at dawnn

The Whitstable Oyster Festival runs from 19 to 27 July. More information from Whitstable's tourist information office, tel: 01227 275482.