Our ship purred upstream on the wide brown river. In the distance beyond the bank rose blue-green mountains, blurred in the heat haze.

On the river bank between the water and the tall green maize were a woman and a water buffalo. The buffalo was strolling, swinging its large head. The woman was patiently following, carefully fanning the animal.

A river journey is a great way to slice through a country. China may be so big as to be unknowable even in a lifetime. But if you want to see a lot in a little time, sailing up the Yangtze is hard to beat. You cover less distance than you would by air. But from a plane you aren’t going to see women in conical hats keeping their water buffalo cool.

And a cruise boat quenches China’s ceaseless hustle. On board, we could take a break from the country’s relentless, pounding, rebuilding drive. Our guide in Chongqing pointed across the river to an empty hillock of brown, raked earth and said: “That will be our new central business district.”

By that stage in our journey, everyone on our tour knew that meant two things. That in a couple of years the slopes would be packed with glass towers and, secondly, that thousands of people would have been given no choice but to move from the homes that had just been knocked down.

Building sites work 24 hours a day. The cargo you see most often in the huge Yangtze barges, which slide down the river like crocodiles, is sand, most likely heading for the mushrooming skyscrapers of Shanghai, near the river’s mouth.

The Yangtze is and always has been a trading highway which also has breathtaking scenery — and not the other way round. So the beautiful and the ugly are mixed. Early one evening, I had to stare hard to make sure I wasn’t imagining things when a human corpse, stiff and bloated, floated past. That same morning we had watched the vast green cliffs of the last of Three Gorges emerge from the mist beneath a pink sky. Your boat feels very small and you feel smaller.

Some guidebooks have claimed that the rise in the water level will make the gorges disappear. With the water coming up 175m (570ft) in 2009, the gorges will not be quite as deep or quite as breathtaking as they were. Having never seen them in their original state, I can only say that they are still going to look pretty good. They certainly aren’t disappearing.

We had begun our journey in Shanghai with a reminder that no one goes to China for gentle weather. A typhoon was sweeping in from the sea and we picked up the boat in Nanjing. The ancient capital is one of the Yangtze’s “three furnaces” and in August the name is not an exaggeration.

But our ship, the Victoria Prince, had air-conditioning robust enough to cope with the challenge and was equipped with facilities to keep demanding Westerners happy: massage, a gym, lessons in mah jong and line-dancing and a resident kite-maker.

The great river scrolls you through China’s vast variety. High up in the river cliffs you see 2,000-year-old coffins poking from cracks in the rock. Nobody seems to be able to work out how this ancient burial custom was done: it would be hard enough with modern ropes and equipment.

We took a long bus ride and queued for two hours to take a swaying cable car up Mount Huangshan, the Yellow Mountain. Surrounded by yelling Chinese tourists with little interest in the landscape, you can see the tall, elegant peaks that inspired thousands of paintings, complete with that distinctive black streaking on the grey-pink rock.

A smaller boat took us up a Yangtze tributary, with steep, forested banks and nobody in sight. We were asked to look up. Two hundred feet above the water a pair of acrobat cyclists edged their way across a wire. Was it a stunt designed to persuade visitors to divert that way? If so, it could only be called “extreme marketing”.

And don’t forget the Three Gorges Dam, because the guides won’t let you. Pharaonic pride in this massive project bombards you with statistics. They mixed concrete 24/7 for 3,000 days to complete it, and it is a matter of some distress that the dam is neither the longest nor the tallest in the world (although the lake behind it will be the largest).

In Britain you had the first ship lock in the 16th century, said our guide, who for the sake of being remembered by foreigners had rechristened himself Kevin on tour buses. We in China are going to have the longest, said Kevin.

We asked about the newly landscaped hill beside the dam. It had until recently been the wrong height and shape. “Knock down mountain, chop chop, like kung fu!” said Kevin. It will soon be a golf course, complementing the martial arts theme park next door.

With the determination that characterises every Chinese change of direction, the country is trying to make itself user-friendly to foreign tourists. Captions in English appear more and more frequently. Those dealing with tourists no longer grimace when addressed in a foreign language, even if they don’t understand it (and basic English is spreading fast among the young). Most impressive of all, there are signs pointing to public loos.

But this is still not quite tourism as you know it; the guides are following a carefully crafted script. Local government is frequently mentioned; central government never. The Communist Party is never referred to. Guides know that environmental protection goes down well with Westerners. A species of small alligator can be found in the Yangtze. The penalty for killing one, a guide proudly told us, is death.

In Beijing, we were taken to Tiananmen Square, where, in beautiful sunshine, perhaps a thousand people were queuing to shuffle past Mao Zedong’s tomb. The guides are just able to admit that Mao may have made a mistake or two, but say nothing at all about any event in the square’s past. Nothing about Mao’s appearance before the crowds as the Communists took control of the country in 1949, nor the killing of students in the square in 1989.

You get a strong sense of China rehearsing for the great rebranding exercise that will be the Olympic Games in 2008, when the country will be on show as never before. After that, the rush to rebuild may even slow down.

Need to know

Getting there: George Brock travelled with Voyages Jules Verne (0845 1667035, www.vjv.com), which offers a 16-night trip, sailing between Shanghai and Chongqing through the Three Gorges and also visiting Suzhou, Xi’an and Beijing. There are departures every week from March to October and the price, from £1,595pp, includes flights, escorted tours and full board.