We're dragging lures behind our runabout miles from anywhere, a long way even from the mother ship, the handsome 53-berth Orion, anchored near Montgomery Reef in the western Kimberley. I'm still shaking a little with adrenalin and fatigue after a hit-and-run encounter with a metre-long queenfish, five kilograms of silver muscle that feints and fights on its way to my feet, where it briefly lies until I can muster the strength to hoist it unharmed back over the side.

That's when someone spots a whale surfacing in the distance. Two! Though this is the breeding ground of the world's largest population of humpbacks, the area is vast and the chance of encountering anything other than sunburn seems remote. Lines are whipped in and we speed in their direction. But they don't surface again.

Lines are recast and the silent trolling resumes.

I've never been whale watching, but I've heard the mammals are naturally curious and sometimes respond to human sounds. "They might come closer if I sing." The fishermen ignore me.

Facing the empty ocean, I hum tunelessly and clap for a while. Someone coughs politely. I feel like a dill and stop.

When the humpback breaches, it's only about 50 metres from us and much, much bigger than our boat. The creature blows a great spout of water, and in our silent amazement we can hear it fall like rain. A smaller whale, the size of a minivan, rises and dips - a mother and calf.

There's a pause. Then the big girl launches into the air - can something with the dimensions of a truck be said to leap? She rises so only her tail is submerged, performs a pike-with-twist exposing a massive midriff, then descends in a gigantic bellyflop. There's a slap of the tail in the ensuing chop, and she dives.

Even before the whale performance it has been a marvellous day, towards the end of a 10-day Kimberley expedition crowded with marvels. We wake just after sunrise on a warm winter morning to the sound of our anchor dropping in another Kimberley bay, each one more remote, more inscrutable. I step from the Orion to an inflatable Zodiac to a beach near Raft Point, where a welcoming party of landowners awaits. They apply streaks of red ochre to our cheeks and lead us up a rocky hill, past a boab that takes the outstretched arms of five people to hug it.

"G'day, I'm Donny," says a man with white whiskers and gentle eyes, sitting under a big sandstone overhang at the top. Donny Woolagoodja is an elder of the Worrorra people, and painted in red and cream ochre on the rock walls around him is the Great Fish Chase of the Wandjinas, the creation spirits of the north-west and central Kimberley. Haunting figures with large mouthless faces and beaky noses, the Wandjinas are surrounded by fish of all sizes. "That one's a barra ready to lay eggs," Donny says, pointing to its swollen belly.

He's the gallery's chief caretaker and artist, and after he explains the story and its lessons of observing seasonal rhythms, he pokes his right forefinger in a bowl of wet red ochre and traces a Wandjina's head. Now in his 60s, Donny was taught by his father, and a son will be allowed to paint the Wandjinas after Donny has passed, ensuring the art and the story live on.

Donny has plenty of stories of his own. He created the Wandjina that rose over the opening ceremony of the Sydney Olympics and, on our descent from the gallery, he talks about his last trip (Las Vegas) and his next (Sydney). Some of his works are in a row of canvases strung between rocks on the beach, selling for up $2000 (conveniently, there's a credit-card machine stationed on a folding table in the sand).

In a land of legendary remoteness (few settlements, fewer roads, no mobile reception for a week), everyone I meet has more than a few fantastical stories and all the time in the world to spin them. The voyage, from Darwin to Broome, turns out to be an intensely social experience. We are a floating five-star village of 168 people: 75 crew - big characters who become briefly but memorably part of our lives - and 93 passengers (106 maximum), almost all Australians, average age about 65, similarly big characters and having the time of their lives.

Gabor, the Orion's Hungarian maitre d' and a central character at every meal, has a talent for cheerful black humour and non-stop conversation. The expedition team, who interpret geology and marine zoology while manoeuvring Zodiacs and spotting sea eagles, tell tales of diving off Papua New Guinea and frozen adventures in Antarctica. Mike Keighley, an award-winning Top End eco-guide, tells stories of his beloved "swamp dogs" (the top-of-the-food-chain saltwater crocodylus porosus), including one involving a couple of female crocs, mud packs and a propeller jacuzzi (I check the story three times and still think he's pulling my leg). Over dinner one night, the dashing French-Tasmanian captain, Jean-Pierre Ravanat, tells tales of crimes at sea and the night his cargo ship listed 55 degrees in an Antarctic blizzard.

Our elegant adventure involves no such privations and I slip into the routine like a saltie at high tide. We cruise pacifically through the night and awake to a new Kimberley vista each day, best viewed with breakfast pancakes at the ship's outdoor cafe. We slip on lifejackets and depart on Zodiacs for a morning's exploration, and return for buffet lunch on the deck (maybe gazpacho, sushi, fresh salads and just-baked bread, Cajun-style fish, prawn stir-fry and a cone of gelato). Then we're back in the Zodiacs for an afternoon of adventure, followed by afternoon tea and team trivia in the lounge at four o'clock (or a soak in the top-deck jacuzzi) and on deck to watch a spectacular and rapid sunset soon after five. There are aperitifs at the bar during the nightly show-and-tell from the expedition team, then dinner from 7.30: four-course degustation menus designed by chef Serge Dansereau of Sydney's Bathers' Pavilion; five-course choices by executive chef Frederic Cyr; elaborate barbecues under the stars.

The first two days are a relaxing aberration. The Orion, registered in the Bahamas, isn't permitted to undertake a solely domestic itinerary, so from Darwin we head for the blink-and-miss port of Com in East Timor, then immediately ricochet back to Australian waters to become engrossed in a strange and phenomenal natural world. This isn't a cruise, we tell ourselves, it's an expedition (OK, with fine dining, marble bathrooms in suites and a masseuse on hand). We float silently in mangrove forests, hike to galleries of rock art, swim in sunlit waterholes. Occasional surprises are manmade: mimosas on a boat anchored near King George Falls; glasses of rum punch and a saxophonist waiting mirage-like on a newly emerged sandbar near Montgomery Reef.

Highlights inaccessible by land or requiring days of driving are delivered back-to-back for eight days. A two-hour flight from Kununurra over the Bungle Bungles is a fine introduction to the mind-altering scale and strangeness of the Kimberley. From the dammed inland "sea" of Lake Argyle we fly over dry plains that resemble a petrified ocean of breaking waves, then over tiger-striped sandstone towers and beehive domes, as mysterious as the ruins of an ancient temple city but unfathomably older than anything conjured by the imagination.

From here, the adventures come thick and fast. We wade ashore at a beach on deserted Jar Island, where crocs often sun themselves, and walk past balancing boulders to three galleries of Gwion Gwion art so old that there's no longer any pigment remaining to allow carbon dating. This is the mysterious and distinctive rock art more often named after Joseph Bradshaw, a lost grazier credited as the first European to describe such art in 1891. On sandstone walls and ceilings are clothes-peg figures, spirits with four fingers and elongated figures wearing high tasselled hats - dynamic and beautiful. There's an echidna and a fish, and a strange pig-like figure that at least one scholar believes is a creature that lived more than 30,000 years ago. Some scholars believe the paintings are far older.

Early one morning we potter up the mighty King George River flanked by flame-orange sandstone cliffs that reappear in perfect reflection around us, and spy a rainbow in the 80-metre waterfall at its head. An hour later we've scrambled up the cliff and are giggling like kids in the pool that feeds the falls.

A couple of days later I wade ashore on lovely Naturaliste Island. A surfer-blond pilot named Will is waiting for me in a little open-sided chopper that rises from the beach like a dragonfly. We keep rising until we reach a vast stony plateau, the most inhospitable land I've seen. By the time I've got used to the proximity of the void beyond my little toe the ground drops away, my knuckles turn whiter and we're flying in front of Mitchell Falls, a four-tiered miracle of water in perpetual motion in a landscape otherwise as dry as a crisp.

"Not bad, eh," Will says with classic Kimberley understatement.

One morning we wake as the captain navigates between forested islands - there are more than 800 of them and much uncharted water in the Buccaneer Archipelago. We drop anchor, pile into Zodiacs and head into a landscape of saturated colour I've only seen before in Fred Williams's paintings. There's plenty of wildlife, but for me the Kimberley is rock and colour, the wildest dream of geologists and artists. The sky is primary blue, the ocean green, the cliffs red, orange, pink, cream. Add red termite mounds, leafless red Kimberley roses, grey woollybutts with silver limbs, sage spinifex. This is the background for a story of phenomenal drama unfolding in cliffs of rock that buckle and fuse at crazy angles, evidence of a continental collision 1800 million years ago between the Kimberley and Australia.

We're being tugged by currents when we see a gap between cliffs in Talbot Bay, and soon we're circling in whirlpools in a kind of Zodiac ballet before the famed Horizontal Waterfalls. In front of us are supernatural rock formations subject to the force of the biggest tides in Australia, a range of 11 metres at some times of the year, funnelling a maelstrom through a 20-metre chasm.

The next day, soon after our encounter with the whales, my fishing buddies recast but can't get a bite. Maybe I did scare the fish. Brad Siviour, our fishing guide, pulls up anchor and we scoot to a main channel off Montgomery Reef, where the rest of the passengers are in Zodiacs, spotting turtles and watching little tidal waterfalls tumbling off the reef.

"How big was your fish?" someone yells at me as we speed past. They don't yet know about the whales. In what will become tonight's tall tale in the bar, I throw my arms wide and shout, "This big!" They take the bait and I add, truthfully, "Between the eyes!"

Helen Anderson travelled courtesy of Orion Expedition Cruises.

FAST FACTS

Orion Expedition Cruises has 10-night Kimberley voyages between Darwin and Broome (and in reverse) from April-September. Fares cost from $9375 a person, twin share (savings available on advance bookings), including shore excursions, lectures, a scenic flight over the Bungle Bungles and all meals. Helicopter flights at two locations are an optional extra.

Phone 1300 361 012; see orionexpeditions.com.