Paul Barney was standing on a sinking ship, feeling it groan and heave beneath his feet. "It was me - just me alone - on the overturned hull of a 15,000-ton ship, waves sloshing, gales roaring. I thought, `What a place to be!' "

Barney, 36, is the sole British survivor of the disaster. "I survived because I was willing to work out what was best for me," he says. While crowds of passengers stood "like statues", waiting to be saved, he made calculations. These people are going to die anyway, he surmised. Better leave them to it.

In his mind's eye, he transformed the upturned deck into a landscape and headed upward. Sliding furniture, smashing ashtrays and stumbling people became tough terrain to overcome. But he managed, hanging on to doorways, clambering across pipes. "I couldn't see anyone, I couldn't hear anyone. Anything peripheral - like people, and what they were doing - was not paramount to me. I was on my own."

Barney came out on to the hull of the ship as it lay on its side. It was a surreal sight, he recalls: rows and rows of windows, some still intact, some broken. Each one was a trap, an opening to an awful death. Instead of feeling fear, Barney felt elated: "I thought, `What am I doing here?' "

Later, curled up in a lifeboat, he felt that sense of elation again. "The moon was out. We were moving away from the ship. I saw the Estonia sticking up on its end, sinking in a red, smoky haze. There was dead silence on the raft. Then someone said: `Isn't it beautiful.' I thought, `You'd have to have guts to say that.' But it was beautiful. I had that sense again, of all the places in the world to be ..."

Now he lives in comfortable Pangbourne, Berkshire, and runs a business as a landscape architect. He has systematically sought to rid his body of every ounce of grief, shock, guilt or pity. He has done it by the book: going to counselling, revisiting the scene, talking to survivors, raising money for relatives of the dead. But it hasn't worked.

When Barney first came back to Britain he was the man who wanted others be rescued first before him. He was the Brit who tried to save a dying Estonian girl. The press wanted details: how he dragged her on board the life raft, held her, comforted her, only to feel her slide away when the boat overturned; how when she was hauled on board again (by someone else) he sat on the other side of the raft and watched her die, her dark hair mingling with the blonde hair of another woman. The press insisted on calling him a hero. His efforts to keep the Estonian girl alive were not "heroic", he says, he was trying to keep himself warm and focused. Yes, he has nightmares, but only recently.

He had an affair. After initial joy - champagne, love letters - the ecstasy evaporated. "I was used to being mothered. I wanted to relax in someone's arms and let the roller-coaster finish. But she had her own problems, and when she tried to talk to me about them I felt they were trivial."

In April, they split up. Only then did the sadness from which he thought he had recovered hit home. Tiny incidents would set him off: losing his way in the car ("I could not even read the map I was so distressed").

There have been happy moments in the past 12 months: realising that a girl he had noticed and admired on the Estonia had survived ("She became the lightness out of my darkness"); and buying his own house, with the compensation money. But none of it is enough to keep him. He has stopped needing to be with the survivors. Much of the camaraderie has worn off. He has stopped wishing he was back on the raft ("For a while it was the only thing that was real, the only thing that mattered").

But he knows now that life in the village is not enough, so he is off again travelling, in search of - what? "That sense of moving from one incredible landscape to another. I need that sense of not knowing."