Nine months before the London 2012 Olympic regatta, Mark Hunter - who has just announced his retirement from rowing at the age of 34 - rowed for his club, Leander, in the Fours Head of the River race on the River Thames.

As he leaned against the wall outside British Rowing's headquarters at Chiswick - the boat in which he and his fellow lightweight crew had come within a second and a half of their heavyweight counterparts safely stowed in the racks made available there to members of Britain's elite - Hunter reflected on the season that had just concluded. And the Olympic season to come.

For Hunter, the Fours Head represented a very satisfying day at the end of what he described as "a really difficult season", albeit that it had ended with another world title in the lightweight double sculls with his fellow Olympic champion from the 2008 Games, Zac Purchase, who had returned to racing after missing most of the season with a viral illness so debilitating that there were days when he couldn't get out of bed.

"We came from nowhere and retained our title," Hunter said. "That shows what a good combination we are. If we can perform next year like we did at the World Championships, the Olympic title is ours to lose. That's the way we are looking at it."

Ours to lose. And lose it they did. By the margin of just 0.61sec after being overhauled by the Danish pair of Mads Rasmussen and Rasmus Quist in the final 25 metres.

Shattered...Great Britain's Mark Hunter and Zac Purchase after defeat at the London 2012 Olympic regatta

The agonies Hunter and Purchase endured during and immediately after that race will have made a lasting impression on many of the millions who witnessed it either from the packed stands of the Eton Dorney course, or via television.

On a day when British rowers maintained their gold standard with victories from the lightweight double scull of Kat Copeland and Sophie Hosking, and the men's four, Britain's golden pairing from Beijing were the very picture of despair after the line, Purchase sobbing with hands over his face, Hunter, eyes hidden by dark glasses, bent blankly over his blades.

Hunter had to be helped out of the boat by Sir Steve Redgrave and team doctor Lady Redgrave and could barely speak to the BBC as he tearfully apologised "for letting everyone down."

The home pair had got away to a great start, but then Purchase's seat had jammed, and as it was within the first 100m the race was able to be re-run. "It didn't have any bearing on the result," Purchase insisted afterwards. But you had to wonder how much nervous energy leaked out of the British pairing as their team technicians worked feverishly to correct the problem.

Whether he likes it or not -and he won't like it, I'm sure - Hunter will always be remembered as much for the circumstances of that defeat as for his previous Olympic and world victories.

While Purchase fulfils the classic profile of a middle class rower - born in Cheltenham, educated at King's School in Worcester, and whose marriage last year to Felicity Hill, now Felicity Purchase-Hill, took place at St Paul's Cathedral and was covered by Hello magazine -Hunter comes from a less exalted background.

Born in Forest Gate in East London, his competitive career began when he when he had joined his local club, Poplar, Blackwall and District, at the age of 14 and proceeded to show a succession of public schoolboys how it should be done.

Mark Hunter - an Eastender - and West Ham fan - who has scaled the golden heights of Olympic and world championship competition

Hunter comes from a rowing family - his brother, Ross, was the 2006 winner of Doggett's Coat and Badge, a single scull event which is the oldest rowing race in the world, having been contested annually on a four and a half mile stretch of the Thames since 1715.

For Hunter, then, life in the world's rowing and sculling elite came from a grounding similar to that of his Olympic forebear Ken Dwan, another Coat and Badge winner, who rowed single sculls in the 1968 and 1972 Olympics and now runs a boat repair business on Eel Pie Island on the Thames at Twickenham.

In 2009, however - the year after Hunter and Purchase had set lose unforgettable in-boat celebration in Beijing after taking gold - this son of the east End (and avid West Ham fan) found himself living the life of Riley.

Hunter was living by a beach in Santa Monica, spending a regular but by no means overwhelming part of his week teaching rowing to novice crews at the University of California Los Angeles (UCLA), the novices all being female, the sunshine being constant.

And when he wasn't been doing that, well, he was partying and having fun, in Santa Monica, in Westwood, in Bel Air, in Beverly Hills...

In short, as Hunter himself said, it was "heaven every day."

For as long as he could remember, this East Ender has fantasised about such a lifestyle. "Since I was a kid I always wanted to travel to California," he said. "I wanted to get away from the UK to relax and enjoy life, and it couldn't have done any better."

The dream job had been arranged a couple of months before the Beijing Olympics, and Hunter left for it just three weeks after those Games had finished in glory.

Mark Hunter (left) and Zac Purchase taste Olympic gold at the 2008 Beijing Olympics

The new career went well. The novices thrived. The UCLA head coach was more than happy for him to stay on.

Hunter had a season ticket to paradise.

And he traded it in for a single back to Blighty.

Thus he found himself in the grinding routine of old, getting up in the dark, braving wind and rain, labouring in the weights room and on the familiar reaches of the Thames.

Why? The lure of a home Olympics.

"That first Olympic win was special," Hunter said. "If we could win again in London it would be pretty amazing. It is going to be a lot of hard work, but we've done it once and we know how to do it again."

Among those who witnessed Hunter and Purchase's Beijing victory was fellow British rower Alex Gregory, who had narrowly missed out on selection and was watching from the stands as a reserve.

"When Mark Hunter won the lightweight double sculls with Zac Purchase I was sitting right behind his brother and his dad and I saw how much it meant to them," Gregory recalled. "They had tears streaming down their faces and they were hugging each other – I can feel myself welling up right now just thinking about it. That made me realise what it would mean to my family and friends if I could win an Olympic gold."

Four years later, as part of the four, Gregory won that gold on home waters – on the same day that Hunter and Purchase lost their Olympic title.

Alex Gregory (left), who watched Hunter win Olympic gold in 2008, earns his own four years later in company with (from left) Pete Reed, Tom James and Andy Triggs Hodge

Among the comments on the BBC website under the story of Hunter's retirement was this one from NJDevilMatt: "The effort he and Purchase put into that epic race last year sent chills down my spine. To hardly be able to stand after competing is how it should be! You should always give everything you have, and more. And for that moment, he will always be in my heart."

There are many who concur with those sentiments. So, Mark Hunter, as you set out for what you call "new adventures", do so in the full knowledge that you have never remotely let anyone down.

Mike Rowbottom, one of Britain's most talented sportswriters, covered the London 2012 Olympics and Paralympics as chief feature writer for insidethegames, having covered the previous five summer Games, and four winter Games, for The Independent. He has worked for the Daily Mail, The Times, The Observer, The Sunday Correspondent and The Guardian. To follow him on Twitter click here.