When American Senator Barry Goldwater set a new fashion some years ago by rafting down the rapids of the Colorado River through the Grand Canyon, he paved the way for a new breed of American professionals to rate this exciting journey as one of their favourite adventure holidays.

The canyon walls rise steeply on either side of the Colorado River, their sheer sides revealing the violent mysteries of the formation of the earth's crust. A mile beneath the jagged rim of the Grand Canyon, two large inflatable rubber rafts drift with the slow current of the waterway. The fourteen people aboard each raft listen intently for a change in the voice of the river. From the near deafening quiet a mere half hour before, there is now a subtle note of urgency. A muted rumbling increases as the surface of the river becomes deceptively calm; stretched smooth by the quickening of the current ahead. The noise becomes a roaring crescendo and the boatman seated at the back of the raft calls the long-awaited order.

"Rapids position!" and the fourteen passengers break into a flurry of activity. Cameras are thrust deep into waterproof cases, hats and spectacles are fastened tightly, everybody obediently assumes their positions on the raft's deck with a secure hold on the guy ropes.