He's one of those jolly captains - like an uncle who's driven you to the seaside for the day, but has promised he'll get you home by teatime. "There's a light mist," he says as he switches off the seatbelt signs at Marco Polo. "Perfect for a romantic weekend in Venice." Then he points out a blur, far away in the lagoon. "If you're sitting on the lefthand side of the plane, you can just make her out," he says. "She's over there, at 11 o'clock." And, for a second, I'm afraid to look. I've left it too long, you see. And now I'm frankly terrified.

Let's get one thing straight. I could have visited Venice before now. Oh yes. Somebody asked me once, 20 years ago. But I was young. What was the hurry? Venice, I said, could wait. Meanwhile, I ate Venezianas in Pizza Express (buy a pizza and save a city), sniffled as Dirk Bogarde died his most famous death, and vowed that, one day, I would find the precise spot where a dwarf put Donald Sutherland out of his misery.

Okay, so I never read much Ruskin. But I certainly looked at his pictures. Also I could tell Titian from Tintoretto, knew a Venetian window from a Venetian blind and was listening to Vivaldi long before Nigel Kennedy started dropping his aitches. Venice was made for me.

Wherever I went, pretend Venices lay in wait. Here was a Venice of the Plains and there a Venice of the Marshes. Every town with a weedy canal and a couple of drainage ditches was another Little Venice. Yet still I was a stranger to the Big One.

And the longer I left it, the bigger it became. What if it was too big to handle? What if I made a big fool of myself (more than one visitor has buckled under the sheer volume of beauty)? But as the years passed, another fear grew in my mind. What if Venice turned out not to be such a big deal after all?

There was every reason to fear that I'd missed the waterbus. "In the last analysis," wrote James Morris in 1960, "the glory of the place lies in the grand fact of Venice herself." And he continued, talking about brilliance and strangeness, melancholia and splendour - about a dazzle that lingers in the mind and a "pink, castellated, shimmering presence" that, "wherever you go in life you will feel somewhere over your shoulder". By 1982, however, the shimmering had diminished and the shoulder had become a trifle cold. "I wish her well," Morris (by then Jan) wrote, "admire her always, hope on the whole they keep her standing: but I am out of love with her."

It wasn't only big-shot travel writers who urged caution. "You have to pick the right time of year," said friends, invariably on their sixth or seventh visit. "We always go in January - it's the only time you can move." Another regular warned of bad food ahead. "Other Italians wouldn't dream of eating the stuff they dish up in Venice," she said. "We're talking tinned mushrooms!"

Reading a Rough Guide before boarding the plane, I knew for sure that I shouldn't be doing this. If I ever made it into the city ("there's a ticket office in the airport, but beware that they'll sell you a ticket for the ATVO rather than the ACTV bus . . ."), I'd be a sitting target for every gondolier and rip-off merchant that ever put pole in water and money in bank. "There is no getting around the fact that Venice is the most expensive city in Italy," said the good book. "San Marco has multitudinous ways of easing the cash from the pockets." And so on.

As I calculate where the captain means by 11 o'clock and squint across the lagoon, I don't know whether to laugh or to cry. ATVO? ACTV? Coming, ready or not.

Dear Reader,

Having a lovely time - wish you were here. No, but really! Two days into my visit, I'm wondering why I didn't come two decades ago.

First, in case you're sick with worry, let me tell you that I caught the wrong bus from Marco Polo - the expensive one, by all accounts. It cost me just over £1.50. Good old sterling, eh? Second, tell my fungally- disappointed friend that I have just eaten fresh mushrooms and even fresher fish and, if she doesn't believe me, she should visit this little Ostaria I found in the Calle Lunga next time she's in town.

Yesterday I went into St Mark's, strolled in his square and lingered among his pigeons. And today? Today, for the price of a small round of drinks in any one of the world's pretend Venices, I have circumnavigated the lagoon. I have visited tiny, half-deserted islands, and passed by structures whose names and shapes are so familiar that I'm convinced my brain has a set of receptors that have been waiting half a century for the appropriate signal. I have floated past mile upon mile of buildings, any 20 of which, set in a row, would double the tourist revenue of all but a handful of towns on the planet.

And wait. Wait till I tell you about this. Tonight, on my way back to the hotel, I heard a two-tone klaxon. "Nee-naw, nee-naw." But where was the police car? Where was the street? And then I saw it - cutting through water as black as sump oil - a police launch with a blue revolving light. Under my bridge it tore, and careered off into the distance, leaving a wash that sloshed and slurped for five minutes around the flooded ground floor of a grounded Byzantine palace. And then a bell rang - a big, beautiful, cracked bell that . . .

But why am I telling you this? I'm forgetting. You have been here a thousand times and it's I who was a Venice virgin.

Five of the best

· Take in the view from the top of the 99m campanile in the Piazza San Marco.
· Catch a water bus to the island of Torcello and see the Lagoon's oldest building.
· See where Futurism meets Surrealism in the Peggy Guggenheim Collection.
· Ogle the fish and vegetable stalls in the Rialto Market, and wish you had gone self-catering.
· Find the Ghetto from which all others took their name (it was built on the site of a foundry - "geto" in Venetian dialect).

The practicals

David Newnham flew from London Stansted to Venice Marco Polo with Go for £110 return, which he booked on the Internet at www.go-fly.com. He stayed at the three-star Hotel Olimpia, 395 San Croce, 30135 Venice, tel: 041 711041, which costs £75 per night for an en-suite double room and was booked through Hotel Connect (020-8381 2233).