The winner of the Samuel Johnson prize had to make a break from a rigid and solitary routine to attend the ceremony

JUDGMENT DAY

I began the week with a stomach full of ferrets. My book Leviathan was up for the Samuel Johnson prize – and the fact that William Hill had me down as the favourite felt like a kiss of death.

I was feeling very superstitious, but as I was walking into the prize-giving on Tuesday night a literary editor knocked a glass of wine over my £1,000 Dior Homme jacket, and I knew that must be a good sign – just as when a seagull poos on you. Even so, when it was announced that I’d won, it didn’t sink in. Someone had to push me onto the stage – and I was so shocked I kissed all the judges.

My books are all about obsessions – Stephen Tennant, Noël Coward, Oscar Wilde – and now Leviathan, about whales. But whereas my other obsessions were dead, whales live on. That makes them the worst obsession of all – they’re like a curse that won’t let me go.

The prize money is like giving cash to a drug addict. I’ll spend it all on trips to the whaling port in Provincetown, Massachusetts, that I visit every year. The staff at the research centre there have identified several thousand whales and I know most of them by name. I can identify them by the pattern on their tails.

CLOSE ENCOUNTERS

I’ve been obsessed with whales for as long as I can remember. A friend of mine said I was so obsessed with them that I must find them sexually attractive and I suppose I do. It’s their power and their silence and their mastery of their environment. And the fact that they can make one feel so insignificant.

To really appreciate a whale, you have to meet it in its element, in the sea. I first swam with whales two years ago in the Azores. I was in a boat with some friends and we spotted a pod of 12 sperm whales. The captain said, “Come on, Philip, this is your chance.” I didn’t have time to put my wet suit on; I just pulled on my flippers and jumped in.

Then suddenly one of the pod turned and swam towards me. It was 50ft long. It was like being approached by a cliff. I knew it could have eaten me whole. This type of whale has 42 teeth and a massive mouth and can swallow a great white shark in one gulp.

It came right up close, then it turned and eyeballed me, sizing me up. There is an extraordinary sentience when a whale holds you in its glance.I had no idea what it was going to do. Mercifully, it decided I wasn’t worth much attention and jackknifed away from me, deep down into the ocean. I was so frightened I wet myself. And yet there was a wonderful, benevolent silence. Mankind has decimated the whale population and I apologised to this one in the water.

THE SEA INSIDE

As a child I was terrified of water. I was too frightened to get in a bath. I’m still frightened of it, but I’m always trying to confront that fear. At home in Southampton I swim every day in the sea. I swim in spring, summer, autumn and winter. It’s a necessary therapy for me; it’s when I sort out all the ideas crashing about in my head.

After the prize-giving I spent the night in London, but I woke up longing to get back into my normal routine. I say “normal“, but in fact it's bordering on the obssessive. I do exactly the same thing every day - unless I'm travelling, each day is identical to the last.

SPLENDID ISOLATION

I wake up at 5.30am and write in bed until 7.30am. Then I get up and have two slices of toast with marmalade and vegetable margarine. I write on until 11am, then I send a few e-mails and have lunch – fish and vegetables – at 12.30pm sharp. Then I have a cup of rooibos tea and sleep for precisely 50 minutes.

In the afternoon I cycle down to Southampton Water to swim and think. It’s not the most picturesque beach – it’s opposite an oil refinery – but the beauty of it is that I’m usually the only person there.

At 5.30pm I have tea and a slice of cake, then I watch some rubbish on the television, have supper at 7.30pm and go to bed at 9pm. You can time my habits with a stopwatch. I never go out and some weeks I don’t talk to anyone at all, but I like it like that.

I still live in the 1930s semi that I grew up in. When my mother died I bought it off my siblings. It’s very quiet and suburban. My only social life is in Provincetown, with the whaling folk. But I’d say I’m pretty happy in my life. What’s the secret? I suppose it’s that I live alone. I couldn’t be in a relationship with anyone. I’d be impossible to put up with.

Philip Hoare won the BBC Samuel Johnson prize for nonfiction for his book Leviathan, published by Fourth Estate at £8.99

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