Kimberley coast cruise: Helicopter hopping around Mitchell Falls, Australia

Floating on my back in the cool waters of the Mitchell River, I see ferns dance by the water's edge and gum leaves shimmer against a cerulean sky. If I were in a movie, the camera would pan back to show the red rocks of the riverbanks, and ancient trees at the canyon edge, twisted into tormented bonsai arrangements by heat and wind.

Then an aerial shot would show the river plunging into a chasm to create an immense four-tiered waterfall, before the camera pulled away even further until the waterfall's grandeur became just a dot in the vast, battered West Australian outback, stark and orange all the way to the horizon.

This is easy to imagine, because an hour earlier I was indeed admiring Mitchell Falls from the air, hanging out of a helicopter without a door and hoping my camera wouldn't be whipped out of my hand into this immensity, only for an archaeologist to ponder over it in another thousand years.

It would take that much time to find a camera hereabouts. We fly for half an hour between ship and waterfall without spotting a single building or telegraph pole or road. There's nothing here but bony earth, the veins of shrivelled-up creeks and knobbly outcrops of rusting rocks.

I'm on a Coral Expeditions cruise around the Kimberley coast between Broome and Darwin, and for days there has scarcely been a sign of human civilisation except for magnificent rock art. The landscape's sheer size and raw beauty makes me feel utterly insignificant, though in a liberating way. Sail through a landscape 2000 million years in the making and petty concerns dwindle to irrelevance. Now I float in the cool water between hot rocks, a mere mote in the eye of the universe.

Australia's great northwest is an endless convolution of bays, sunken valleys and islands that blur into one another and erupt in occasional moments of total splendour. Mitchell Falls is a highlight, accessible only on this optional helicopter flight. I don't hesitate long to sign up. The Kimberley is a one-off experience, and what's the alternative? I could drive for days on dirt roads, and camp, and then walk for hours to see it. Instead, I'm staying in luxury on Coral Discoverer, enjoying red wine and steaks, sunset sailing and helicopter hopping.

The helicopter picks us up from a beach in Mudgee Bay. From the air, the Mitchell Plateau is scattered with fan palms, white gums and long strings of paperbarks that mark meandering water courses. At Mitchell Falls the water simply plunges over the escarpment. We swoop over it in circles as spray rises. If only this waterfall was more accessible, it would be far more famous.