Somewhere between Byna Bo and Raap en Skraap, on the long flat stretches that typify this section of the Orange below Augrabies Falls, the river spoke to me in a tempting voice. Its breath brushed my neck with the musty scent of densely packed river reeds, and a faint murmur of wind troubled the surface of the khaki-coloured water. Listen, it said to me, there's everything you need in this endless emptiness - why go back?

We all have what we call our "normal" lives with homes that get cluttered up with stuff we think we need. We have our emotional attachments, jobs and financial complications. Where does it all get us? Not often where we want to be!

The long Mohawk canoe nosed into a cool, shady grove beneath some overhanging Cape Willow trees as I waited for the rest of the party to catch up. There were three dozen of us, a big party, of whom half were teenagers or younger kids. They were with their parents, doctors or other medical personnel, hailing from Durban.

The party included the editor of South African Paddler magazine, Marc Cloete, whose enthusiasm to master “Tupperware” whitewater kayaking was infectious. He soon got the Eskimo roll and on the last day played happily in the surfing waves at Graduation Rapid. Two of us guides carried plastic kayaks strapped on top of the Mohawks, but hardly used them because the river was pretty low.

That didn’t bother our boisterous bunch of canoeists. Assembled by Janet and Chris Pearse (an eye specialist), nothing phased them. Long distances, rocky shallows, tricky turns between boulders: it was all in a day's hard fun. The youngest kid was a mere four years old, paddling with his Dad, and make no mistake this was a future Iron Man in the making. The whole party had paired up in the two-seater canoes, Moms with sons, husbands with wives, girlfriend and boyfriend (at night in the tent too).

What tolerant parents; but then I suppose if you're in the medical business you sort of accept the natural expression of the sexes - and what better place for it than the wilderness?

Distance made the canoes look like a flock of ducklings fluttering their paddles in the hot sunlight. Whenever we ran the tight, rock-strewn rapids, the instruction went out, "Ducks in a row!"

But now the atmosphere was sultry, the river shimmering in stillness. Great broken koppies of pink quartzite and red granite sailed by, with the occasional cry of fish eagles cutting the air like wake-up calls to dozing canoeists. Sometimes we plunged into the waist-deep water like otters. Or just drifted in the boats, letting the mild current do the work. On the long, long haul of 7 km of flatwater to Skuitdrift weir the paddlers set their jaws and kept going, arriving sunblasted but happy for the resupply of food and drink marking the halfway point of the trip.

Andrew Hockly, owner of Kalahari Adventures, was standing there under a wispy tree showing a big smile. His wild, curly grey hair makes him every inch the ageing hippie, tanned and fit under the desert sun. He'd asked me to run the trip for him because the logistics of transport and food packing were complicated for such a large group and he needed to manage it personally.

Skuitdrift lies in the lee of an amazing granite pyramid whose layers of basement rock have been shattered into massive blocks. It fairly throbs with heat, absorbing all the sun can throw at it. The mountain’s natural grandeur beggars the work of the Pharoahs and strikes awe into the hearts of mere canoeists. Dwarfed by the surrounding scenery with its eerie noonday silence, even the shouts of the kids playing water polo above the weir are muted and quickly swallowed up.

It was this memory of the Kalahari’s overwhelming power that prompted me to take up Andrew’s offer. I’d been on another mission – to buy a plot of land next to the river near the town of Kakamas – but the temptation to get away into the great outdoors was too much to turn down.

It was at least 27 years since I had first explored the route from below the Augrabies Gorge down to Onseepkans, the border post with Namibia. Beyond Onseepkans is the majestic and terrifying Oranje Gorge, featuring the little known Ritchie or !Gariep Falls – a stretch I knew well from running many river guide schools there in the 1990s, and also from regular kayaking and rafting trips on the big whitewater of the gorge over several decades.

But I had only the haziest memory of the route to Onseepkans. I warned Andrew that I'd probably lead the party into trouble. Don't worry, he assured me, his guide Jerome knew the way and would be accompanied by Jannie who was doing his first trip as a handlanger or general dogsbody. The guiding party of four was completed by my foster son, Damian, 19, who had won his guiding ticket on the rapids of the Vaal River at Parys, where we live.

Jerome turned out to be the guide's guide: he knew every trick of the island mazes, and at the same time was a brilliant chef and camp maker. Jannie's talent was catching yellowfish to supplement his dinners. Damian meanwhile involved himself with the youngsters, organizing an Easter egg hunt on the last morning. The four-day trip ended on Easter Sunday.

The four guides each had a fully loaded Mohawk that they paddled alone, carrying the enormous junk of a large fully-catered holiday camping trip. Tables, braai grids, cooler boxes packed with T-bone steaks and even bags of Bar Ones served to remind us that you don't leave the trappings of civilisation behind too easily.

In these heavily laden barges, river rescue in wild water would be almost impossible. They take as long as a tanker to turn and I'd decided that if rescue really were needed anywhere in the small rapids between islands, I'd hook the boat to the reeds and wade out or swim. But we only had one rescue in the whole trip when a couple misread a small drop and turned turtle in the stopper wave below.

The channel below was deep and wide, and they were quickly fished out by Jerome who was sitting waiting there for just such an upset.

The Orange is one of the world’s greatest tripping rivers. So I think after writing White Water: The world’s wildest rivers (Struik New Holland, 2000) which covers the best river routes on every continent. The remoteness of the Lower Orange, its stark beauty set amid a landscape scarred by time and violent erosion, gives it a special spiritual appeal. It speaks to you – sometimes in whispers, sometimes in a roar.

It can be dangerous too, maybe more so because it lulls you into complacency. On the second night I came in at the end of the party, having shepherded a few tired boaters to the night-stop. By the time I pulled up on the beach, tents were up and everyone was beginning to relax in the warm embrace of evening with coffee and cocktails.

But there was lightning all round the horizon. To my horror I realized we were camped in the floodbed of a river – now dry, but whose debris could be seen tangled in the branches above our heads. Taking a deep breath because I knew the order would be unpopular, I asked everyone to move their tents to higher ground. The men uncomplainingly hauled the deadweight Mohawks up to a sandy shelf, building up a great beer thirst.

Nothing happened that night: there was no flood, so my shares were pretty low by morning. Yet when we hiked up to Minus 4 – an astonishing pinnacle of granite like the Big Toe of God with no other toes around it – the view from the top revealed not one riverbed, but two, converging on our campsite. Whole parties have been killed in flash floods that come from storms far away and arrive as a wall of water without warning.

Never trust a river, but listen to its voice.

• Graeme Addison