A couple of years ago Philip Hoare, now 55, found himself digging around in a sideboard in the semi-detached Southampton house in which he grew up. He was surprised to find a blue notebook that had belonged to his father, who worked as a cableman all his life, but had been commandeered by the teenaged Philip. "Alongside the blank verse and stream of consciousness lyrics were doodles: pictures of whales, 70s glam-rock stars, 1920s decadent figures – all of my obsessions. The whale I'd painted in poster paint using my mother's clear nail varnish to make it look slicker and shiny as if it had just come out of the water. It's really remarkable – the whole of my career planned out at the age of 14. I thought: why have I bothered?"
For a long time it seemed Hoare's career was anything but planned. His non-fiction output has ranged widely in subject matter, beginning with Serious Pleasures: The Life of Stephen Tennant (1990) about the "brightest" of the 1920s Bright Young People, an aristocratic lover of Siegfried Sassoon who spent 17 years in "decorative reclusion" after the second world war. Then came Spike Island: The Memory of a Military Hospital (2001) and England's Lost Eden: Adventures in a Victorian Utopia (2005), both of which are atmospheric and at times ghostly cultural histories of deep Albion. More recently he has turned his attention to cetaceans with Leviathan (2008) – winner of the Samuel Johnson prize for non-fiction and catalyst for the Moby Dick big read in which the likes of Tilda Swinton and David Cameron read aloud Herman Melville's novel – as well as his newly published The Sea Inside.
Hoare's own background is far less exotic than many of the topics he has broached. "Southampton is a weird place. It was the fourth most bombed city in the country and littered with bombsites. It often feels like a place of transit, of not being in the main current of things. It's strangely marginal but important at the same time because of its relevance to the history of Britain and to the history of immigration and emigration. As a schoolboy I was a daydreamer; I'd dawdle to school and think about what lay beneath the pavements – how many layers you'd have to go down before you'd reach the Roman occupation."
Hoare, who won a scholarship to a monastery school, claims he used to be a snob. "It's terrible but I remember looking at my father's wage slip to see if he'd earned enough to be middle class." Real emancipation came through watching TV. "David Bowie appeared on Top of the Pops with Mick Ronson and I remember thinking: 'What universe is that happening in? How can they be together?' I'd get my mother to make me pink satin Oxford bags, which I'd wear with platform shoes on the bus going into town. My education came from him as I learned about William Burroughs, Andy Warhol and Jean Genet. Just like Oscar Wilde, he commodified dissent for the suburbs."
After Hoare took part in a conversation about Bowie for the book that accompanies the V&A's current exhibition, a curator invited him to the basement to look at the singer's costumes. "There lay a cross between a plywood cradle and a semi-circular, space-age coffin. Like the casket of a mummy. In there was the Pierrot costume for the "Ashes to Ashes" video. It was made of buckram and silver fabric and sequins, but it was stiff and looked like the chrysalis of an insect which had vacated it. It was in the shape of David Bowie, as if he'd been teleported out of this world and left this reliquary we were worshipping. I reached out but I couldn't touch it. It would have been too much. It would have broken the spell."
In 1976 Hoare moved to London to attend St Mary's College, Strawberry Hill, where he edited an anti-racism journal. He describes the capital as part-fantasia, part-wasteland, a city – like his evocation of Mary Ann Girling's New Forest Shakers in England's Lost Eden – that could be seen as either scary and threatening or as being fertile with dissenters and visionaries armed with new designs for living. "I lived on Beck Road in Hackney; Genesis P-Orridge's wife Paula would sunbathe topless on my balcony. The National Front seemed to be everywhere. You could easily be set upon by skinheads. I used to take a penknife in my pocket every time I went to the Roxy: only for a few hours at night and in the early morning could life became what you wanted it to be. We were utopians."
After college he worked for Virgin where, as an independent singles buyer, his decision as to whether or not to purchase an entire pressing of a single could make or break a band. Soon he was poached by Rough Trade and also given money by Michel Duval, owner of the iconic Belgium-based label Les Disques du Crépuscule, to establish Operation Twilight, a label he calls "a work of fantasy" and whose arty, heavily European roster included Antena, Paul Haig, Tuxedomoon and the Pale Fountains, a Liverpudlian band he also managed. "I had no business sense; it was just a great way to get Howard Devoto to come to your house and talk about publishing a book."
It was around this time that, having been christened Patrick Moore, he became Philip Hoare. "Imagine having to spend your entire life living with people asking: 'You're not that astronomer, are you?' Or: 'Do you play the xylophone?' Another reason was that when I was managing bands I used to review my own bands for the NME and Sounds as Philip Hoare. Philip was my confirmation name; Hoare my mother's maiden name – Anthony Burgess did the same thing." Is there a difference between his two personae? "Philip Hoare writes books and goes places. Patrick Moore goes along with him but secretly wants to go home at 5.30 and have a nice cup of tea and a piece of cake – and go to bed after watching Antiques Roadshow."
By the mid-1980s, Hoare was writing for style magazines such as Blitz and The Face, documenting demi-monde London and living what he calls a "dissipated" life. His book about Tennant portrayed dandyism less as eccentricity than as experimentalism or modernism. Its subject, whom VS Naipaul in his novel The Enigma of Arrival (1987) had depicted as a symbol of post-imperial English torpor, emerged as a magnetic field, a zone of possibility and conjecture. "I decline to judge on the part of my reader," Hoare says. "I'm just a conduit between the reader to whom I tell a story and the perceived reality of what I saw. I know I make things fantastical: the sense of being objective is impossible."
Hoare grew up reading the ghost stories of MR James and cites outsider archaeologist TC Lethbridge's definition of a ghoul as being the spirit of a place. He often talks about being "possessed" by his subjects, and is happy to say he believes in ghosts and other occult forms. It is this kind of language that distinguishes his books from those of left-field topographers of avant-Britannica such as Patrick Wright. In fact, his associative landscape drifts have led reviewers to liken him to a less crepuscular WG Sebald.
"Sebald was a huge influence on me, but a late influence," Hoare recalls. "After Spike Island, I read The Rings of Saturn. That changed everything: it made what I did allowable. As with Bowie, it awoke something that was already there. I remember getting a letter – postmarked Norwich – and in it a postcard signed by someone called Max saying how much he'd liked my book about the military hospital. I had this fitful conversation with him by letter: he was encouraging to me and I thought I'd found a mentor, but just a few months later, at the end of 2001, he died. I met him a few months earlier at Queen Elizabeth Hall: he said that mine was a really good book and that 'I hope you don't mind if I steal bits of it'. I'll never know what he was going to steal."
In recent years, Hoare has turned his attention to maritime spaces from which, he believes, we have become disconnected. "You could come to Southampton and you wouldn't see the sea. There's an economic, spiritual and psychic separation there. Water is the cesspit of modern culture – the place we dump stuff and pump pollution. I'm not George Monbiot: I'm not a campaigner, but I feel this psychically and spiritually. When you swim in the sea you see it as the cosmos floating all around you. We are ghosts, invaders in a way – but as individuals we have very little power over it."
The Sea Inside – equal parts memoir, travelogue and nature meditation – is perhaps Hoare's most lyrical book. His friend the American film-maker John Waters says admiringly: "He writes about birds like a gay man might write about his best trick. And he writes about whales so beautifully and sensually he has to be careful: pretty soon he's going to have sex with an animal. I tell him he writes whale porn; it's better than any erotica that's ever been written. He makes his passion like an illness, like a good illness."
Hoare himself believes that the book, which takes in journeys to Sri Lanka, New Zealand and the Azores, is essentially about "the sense of what is home". He wrote it in his childhood bedroom – now his study – in Southampton. "When I walk through the front door it's like stepping back 55 years. It smells of home. Tangibly, aurally and olfactorily – it is my past."
The Sea Inside is published by Fourth Estate.