Is that Moby I see before me? Or is it just a great white whale?

You'd be amazed who you run across when you go in search of Moby-Dick. Philip Hoare has a chance encounter on the way to New England...

Catching a bus to the Lower East Side, I call at TeaNY, a café in now fashionable Rivington Street, owned by the pop star Moby - and find myself sitting next to the man himself. He's a personable chap; his geeky glasses, polo shirt and jeans belie his calling. Only the crucifix tattooed on the back of his neck gives the game away. Moby tells me that his nickname comes from a family link to Melville, although he's not sure now how true the story is, and in reply to my request for clues, sends me in the direction of Herman Melville Place, "somewhere in the East Twenties". I duly find the site, along with an obscure brass plaque marking 104 East 26th Street - the address where Melville spent his final years as a New York customs officer. A sad, land-bound end, perhaps; but maybe he had said all he had to say.

It was time to leave town. My artist friends Megan and Duncan just happen to live close to the Berkshires, the idyllic Western Massachusetts countryside where Melville met his hero, Nathaniel Hawthorne, at a picnic on Monument Mountain in August 1850. We climb the same summit, where a larky Melville thrilled Hawthorne by wielding an imaginary harpoon. The usually reclusive Hawthorne was smitten; it was the beginning of an intense relationship that would have a vital impact on the writing of Moby-Dick. Melville moved to the Berkshires, and from his house, Arrowhead, he could see Mount Greylock, whose broad, grey summit reminded him of a whale. The place is now a museum, and in the room in which he wrote his epic, I'm moved to find a trunk labelled H Melville in fading sepia, and a blackened harpoon with which he stoked his fire.

In Boston, I meet another friend, Mary Martin, and we drive to Concord. This is the home of the American Revolution; but it was also where Hawthorne spent his early married years in a house rented from Ralph Waldo Emerson. The Old Manse is scented with ghosts; its ancient windows are etched with graffiti carved by Sophia Hawthorne's diamond ring. Close by, we swim in the still, deep waters of Thoreau's Walden Pond.

Hawthorne, Emerson, Thoreau and Louisa M Alcott are all buried in Concord's Sleepy Hollow cemetery; it is easy to conjure up their ghosts, and others, in New England. That night we drive to Fall River, and check into the Lizzie Borden bed and breakfast - the very house in which Lizzie is supposed to have taken an axe to both her parents. Guests can sleep in Mrs Borden's room - with a photograph of her body lying on the carpet - or take tea downstairs, next to a photo of Mr Borden's bashed-in head. Yet the current proprietors are a cheery and welcoming bunch who have learnt to live with the house's sometimes noisy spirits. "After all, they were here first," our landlady tells us. "Why should we tell them to leave?"

We drive on to neighbouring New Bedford; now a rather forgotten place, but in the early 19th century this was the richest city in America, wealthy from whale oil. Here, at Christmas 1840, 21-year-old Herman Melville signed up for his first whaling voyage.

The entire downtown district is now a national park, its jewel is its whaling museum - the best of its kind in the world. Visitors are greeted by the suspended skeleton of a 50-ton blue whale, which washed up at nearby Rhode Island in 1998. The oil still drips from its bones. Inside is an extraordinary collection of scrimshaw - whales' teeth carved by sailors on their three-year voyages. There is even the desiccated, yard-long penis of a sperm whale. Across the street is the Seamen's Bethel - Melville's " Whaleman's Chapel", complete with memorials to drowned sailors; and nearby are five blocks of ornate whaling captains' mansions with roof-top "widow's walk" balconies, supposedly built to allow their mistresses to survey the seas for their loved ones. Melville wrote of "all these brave houses and flowery gardens ... One and all, they were harpooned and dragged hither from the bottom of the sea." And as we pass another embellished pile, Mary wonders, "How many whales did it take to build that one?"

Faintly appalled at the notion, we leave for Cape Cod, another historic centre of whaling. Once you could almost cross the bay on the backs of northern right whales (so named because they floated when dead and were the "right" whales to catch); nowadays there are barely 300 left, and their gene pool too restricted to sustain their species beyond this century. At Provincetown's White Horse Inn, a whaling captain's house from the 1830s, the proprietor, Frank Schaefer, produces a thin, ruler-like object he found behind some panelling: a whalebone busk, carved by a sailor to stiffen his sweetheart's corset. It is a poignant relic.

But Provincetown's whaling past has a more positive future. It is one of the best places in the world from which to see whales, and its renowned Center for Coastal Studies supplies naturalists to commentate on board the Dolphin Fleet's whale-watch boats. It is a relief to see living whales at last. Out on the ocean, humpbacks breach - "the most gamesome and light-hearted of all", according to Melville - and 80ft fin backs slice through the grey-green sea like living torpedoes.

After a week's close encounters with cetaceans, Mary and I fly to Nantucket. Flung like a boomerang into the Atlantic, this island saw the departure of Ishmael and his tattooed cannibal mate, Queequeg - although Melville never came here until after he had written Moby-Dick. Nantucket's cobbled Main Street looks more like Thomas Hardy's Wessex than modern America. Mature trees stand beside 200-year-old clapboard houses. But there is a sense of withheldness - "like a town dignitary greeting visitors", says Mary - which gives little away. This was a Quakers' settlement, determined by plain and simple values although pacifist beliefs did not jar with their cetacean holocaust.

We ride on hired bikes to the farthest beach at Sconset (the locals' abbreviation for Siasconset). Here the island ends. Nothing lies ahead but the Atlantic, and the yawning blue sky. I ask the lifeguard, perched high on her white chair, if she ever sees any whales from up there. She almost laughs as she says no, not ever. But I don't believe her. Isn't that a white head rearing out of the spume, shooting its ghostly spout up into the air?

Give me the facts

How to get there

The writer flew as a guest of Virgin Airlines (0870-380 2007; www.virgin-atlantic.com) to New York and back from Boston. Return fares start at around £386. Cape Air (001 800 352 0714; www.flycapeair.com) flies daily to Nantucket from Hyannis with day returns starting at $89 (£50).

Where to stay

The Soho Grand (001 212 965 3000; www.sohogrand.com), 310 West Broadway, New York, offers double rooms from $524 (£291) without breakfast. Double rooms at Lizzie Borden's Bed and Breakfast (001 508 675 7333; www.lizzie-borden.com), 92 Second St, Fall River, Massachusetts, start at $248 (£137) with breakfast.

Further information

Massachusetts Tourism (001 617 973 8500; www.mass-vacation.com).