I'm a Canadian. I was born to paddle. An eight-day white-water-rafting trip down the Zambezi is supposed to be like an amble down the high street for me, a leisurely jaunt along the watery border between Zambia and Zimbabwe. Just the sun, three rafts, 16 people and a copy of The Compleat Angler.
The full horror of the situation hit me while I was sitting on a cliff overlooking a rapid called The Washing Machine or The Devil's Toilet Bowl or one of the other suitably macho names given to the churning pits of aquatic terror. It had just flipped three boats in a row.
But it wasn't the rapids I was scared of. Or the two crocodiles we'd seen upriver. Or the malaria-carrying flies. Or the poisonous snake that had managed to bite an ex-British Army officer before we could pummel it to death with our paddles. Or even the sense of humour of our river guides, invariably Australians.
No, what really scared me were the hippos. Forget your images of cute, waddling, grey hippo-teddies. These things kill more people in Africa than any other wild mammal. Hippos spend 60 to 70 per cent of their days in the water. But not only can they not swim, they can't even float. They can, however, stay underwater for up to six minutes. Often, all you can see of a hippo are two golfball-sized eyes bobbing on the surface.
Usually, if a hippo senses you are entering his area and doesn't like it, he'll mock-charge. This mostly involves bouncing off the bottom of the river, snorting water and grunting. In the words of Max, one of our river guides, "When performed by two tonnes of highly irate hippo, it's a surprisingly effective warning."
Sometimes, though, there is no warning. "I saw a canoe get hit by a hippo," Max told me. "It was just gliding along in the middle of the river. No noise. Then, boom. There's noise. There's water. People are screaming. It's quite hectic, eh?"
What Max saw was a fairly standard hippo attack. Imagine a Zambian fisherman poling down the river in his dug-out canoe. He is approaching a hippo who has been underwater for four minutes. The fisherman doesn't see him and sticks his pole into the hippo's head. The enraged hippo opens his jaw wide, pulling back his blubbery lips - yes, this is where the lips come in, they are extraordinary. Exposing his murderous teeth, he surfaces violently, driving his 10in-long lower canines though the bottom of the boat.
If he is lucky, the fisherman will be thrown clear. Many though, don't survive the attack, largely because most people living near the Zambezi don't know how to swim.
So is that it? Do river-users just let themselves get terrorised by these curvaceous beasts? Some, such as Hugo, yet another Australian river guide, take solace from a quirk of Victoria Falls geography: "Hippos have been known to drop over Victoria Falls, hit the bottom and explode. It'd be good to see."
Nothing like a respect for nature in all its glory. Now if only they could do something about the crocodiles, poisonous snakes and Aussie jokes. The flies I am used to. After all, I am Canadian. Cleo Paskal
Air Zimbabwe (0171-491 0009) and British Airways (0345 222 111), fly between Gatwick and Harare, with connections to Victoria Falls.