'The water was up to my neck. I thought: This is it'

Graham Hancy said he had no idea of the identity of the man who heroically went to his aid and then disappeared without leaving his name. But he added: "I want to shake his hand."

It was later revealed the heroic passer-by was David Quaterman, a 42-year-old contract worker.

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"I could see someone struggling behind the glass, it was misted up but I could see hands on the windscreen," Mr Quaterman said.

"I ripped off my high visibility vest and took off my steel-toed boots and jumped in."

"I think the man was in shock," he told the News of the World. "He seemed more worried about keeping his fags dry. He was holding them above his head."

Mr Hancy had driven his Mitsubishi 4x4 under a low bridge in Gloucester when he smashed into a Citroen car which was already submerged.

The collision pushed both vehicles further into the water and his engine died as his 4x4 was spun 180 degrees by the rising torrent.

Mr Hancy, a machine-operator at a recycling plant in nearby Tredworth, said: 'I saw the water at the last minute because of the low dip in the road from it being under a bridge.

'But I was pretty confident that I could go through it in the Jeep - until I suddenly smashed into something under the water.

'It was only then that I realised there was another car. It had been completely invisible. I tried to reverse but the engine died on me. Then I felt the car being carried by the flood water and it spun around. The water rushed into the front seat and in a matter of seconds had gone from my ankles up to my waist.

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'I tried the doors but they wouldn't open. So I clambered into the back - there was no time to panic. I was kneeling down trying to do the doors, and clambering about in there. The water was up to just below my waist.

'The back door was locked and I was starting to think, 'This is it.'

'The whole of the front was near enough submerged. Then I saw the electric sunroof and clambered towards it. The water was nearly up to my neck and I was running out of options. I pressed the button and the roof whizzed open.

'It was only then that I saw a stranger had stripped off his shirt and swum over to rescue me. I am a good swimmer but he really helped me out by helping me to drag myself out of the sunroof. He didn't say who he was. He said, 'Are you all right?', and I said, 'Yeah, I'm all right'.

'It was only when I got out of the car that the cold hit me. We swam about 20 yards and I was able to stand by the road.

'Someone offered me a blanket and I said, 'No, thanks.' Then I turned around to thank the guy who had rescued me but he had gone. It was amazing.'

Mr Hancy's vehicle was now fully submerged. A former grasstrack racing driver, he knew then that he had been more than fortunate.

'I had some prangs in my racing days, but I have never come this close to death. That could have been my watery grave.'

Mr Hancy later returned to the vehicle. 'The car's a bit of a mess, a bit dirty inside and outside,' he said. It was due to be removed by a truck.

At home with his wife Lesley and stepsons Blake and Ben, he said: 'I would love to meet the guy who rescued me to shake his hand. Lesley and I only got married two years ago and our anniversary is in two weeks' time. To think that I came so close to not being around for that is terrifying.'