The invitation was irresistible. “Come and inspect the new Olympic Stadium — by boat!” said Tony Hales, chairman of British Waterways. So last Friday, precisely 1,001 days before the opening of the 2012 Games, I took up his offer.

It was a weird and wonderful excursion for many reasons. First, because after you leave the Thames at Limehouse you glide along such exotic waterways as the Bow Back Rivers, the Three Mills Wall River, the Limehouse Cut and the Bow Creek, which brings you back to the Thames east of the Isle of Dogs. They used to be labelled London’s “forgotten” rivers. But that was before the fateful moment when London won the bid to host the Olympics, and these forlorn marshes were suddenly earmarked as the site of the biggest media show on Earth. Even three years ago, when I cycled round the area, it was still an inhospitable wasteland, crisscrossed by putrid streams and pockmarked by industrial debris and derelict factories.

The transformation is breathtaking. The rivers and canals sparkle. Towpaths have been mended, bridges painted, fish frolic, and the reedbanks are a twitcher’s paradise. There are joggers and cyclists everywhere, and even one of those coveted icons of trendy urban living: a Banksy graffito. True, the yuppyish waterside apartments rising everywhere — all bijou balconies, kindergarten colours and faux-distressed wood — strike me as aesthetically shallow and already a bit dated. Yet undeniably they are a quantum leap forward from the smashed-up warehouses they replaced. And the impressive lock just completed by British Waterways at Three Mills has made this network of little rivers navigable by big barges again. So nearly two million tonnes of the construction material needed for the Olympic site can be transported by water, saving an estimated 170,000 lorry journeys on some of London’s most congested roads.

All that will gladden the heart of any Londoner who, like me, has watched the depressing 50-year decline of the old East End — fatally dependent on the dying docks, the Kray gang and other doomed industries. And it’s good for everyone else as well. There’s only one effective way to stop housebuilders concreting over every blade of grass in southern England — and that’s by making hitherto down-and-out areas of our towns and cities attractive to the aspiring middle classes. Irrespective of the Olympics, the regeneration going on in gritty East End boroughs such as Hackney, Newham, Waltham Forest and Tower Hamlets is of massive significance. It means that London can continue to expand — but expand inwards, not across the entire Home Counties.

Of course, nothing is “irrespective of the Olympics” in London now. A massive area, about 500 acres, has been turned into a giant fortified building site. The only way to get even moderately close to the action is to do what I was privileged to do: creep along the Bow Back Rivers by boat. That way, you get right alongside the main Olympic Stadium.

The good news is that it seems remarkably complete — at least as far as its outer shell is concerned. The bad news? Well, it also looks much like every other big British stadium constructed in the past 15 years. It’s early days, I know, but nothing about this workaday design promises to be as heartstopping as Beijing’s amazing bird’s nest.

If you want architectural daring, however, the groovy 160-metre curved roof of Zaha Hadid’s hugely controversial Aquatic Centre can also be glimpsed from the waterway. And glimpsed it certainly should be. At £303 million, it will be the most expensive swimming pool in the history of Western civilisation.

And all around these two mighty structures is less glamorous evidence of the Olympic Park’s vital infrastructure taking shape. Right now there can’t be a bigger or busier building site in the world. That’s heartwarming to see. The sceptical wag who manufactured T-shirts with the slogan “London Olympics — 2013” may yet be confounded.

All of which is good news for me. Eight years ago, when it seemed as if Britain might wimp out of bidding for the Olympics altogether, I wrote an article on these pages lambasting the “can’t do” and “won’t happen” mentality that I felt was enervating the political and media classes. A series of spectacular fiascos — high-profile construction projects, such as the Millennium Dome, Scottish Parliament, British Library and Wembley Stadium, that had gone hundreds of millions over budget — seemed to be turning us into a nation so paralysed by defeatism, so hard-wired for mediocrity, that we believed ourselves incapable of realising our grandest visions.

That struck me as pathetic. The last time we hosted the Olympics, London was still a bombsite, food rationed and the nation all but bankrupt. We still put on a damn good show. I felt it was mad to let the Olympics go to Paris — to the French, for heaven’s sake! — without even a whimper of a challenge.

But it would be dishonest to say that in the years since then my faith hasn’t wavered. Budgets have soared, politicians have squabbled and prevaricated endlessly, high-powered planners have strutted in and flounced out, and blueprints been rewritten more times than Liz Taylor’s marriage certificate.

So what I saw on my boat trip last week was massively reassuring. It’s now impossible to feel that, with 996 days still to go, the Olympic Park won’t be completed on time, and completed with distinction. Oddly, the financial turmoil of the past year may have helped, not hindered. With the building industry in the doldrums, construction costs can surely be squeezed downwards. We taxpayers may yet see some change out of ten billion quid. Two years ago that figure (four times higher than the original estimate) produced howls of fury. Now, after the £37 billion we have spent bailing out the banks, it looks quite reasonable.

But it’s one thing to have the bricks and mortar in place, quite another to win hearts and minds. Talking to people up and down the country I’m struck by how much the 2012 Games is still perceived as belonging to London alone. Not long ago I chaired a public meeting in Birmingham to discuss how lottery money was being spent. I asked the audience to raise their hands if they thought the 2012 Olympics would bring any benefit to people in the Midlands. There were about 200 punters in the hall. Not a single hand went up.

The newly-launched plan to stage 60 big sporting events in 20 cities across the UK between now and 2012 may help to enthuse sports fans. But millions of sceptics around Britain, and even in London, remain unconvinced that the Olympics will be anything other than a colossal waste of our money, at a time when few people have cash to spare. Whoever wins the next election will need to embark on an urgent campaign of mass persuasion if the 2012 Games are not to be tarnished by widespread resentment.

Me? I’m just hoping that I can borrow the British Waterways boat to get to the Olympic Stadium when the Games start. Well, would you trust the trains?

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