When Sir David Attenborough describes a unique part of Western Australia as 'one of the greatest natural wonders of the world', it pays to listen up. He was talking about the Kimberley's Montgomery Reef, stretching for 400 square kilometres along Australia's remote northwest coast.
We experience the Kimberley's amazing natural phenomenon, first in one of the True North's purpose-built 'adventure boats,' and then in a spectacular helicopter flight departing from the stern of the luxury vessel.
Over just a few hours, the southern hemisphere's largest and most rapid tidal movement has taken place, transforming a marine-scape inhabited by sea turtles and manta rays, and causing an ocean maelstrom to surge across the reef's indigo-coloured coral. High above, in the True North's chopper, horizontal cascades score the reef's meandering profile, and pilot Rob Colbert is pointing out sharks and dugongs basking in the sun-warmed waters below us.
Two days earlier we'd first boarded the True North via the shallows of Broome's Cable Beach. We arrived on the boat for a first night greeting combining seared scallops, Margaret River wine country bubbles and a sublime West Coast sunset. Fast forward twelve hours and waking up to a Kimberley sunrise has revealed cobalt waters and a remote red-earth landscape as we continue on a week-long journey north from Broome to the isolated port town of Wyndham, exploring the natural highlights of a region regarded as Australia's greatest wilderness area.
Life on boat the 50m-long expedition boat soon assumes its own compelling rhythm. Rise early for another spectacular Kimberley dawn, with the sun shifting over a leviathan and labyrinthine coastline, before breakfast in the dining room with the boat's maximum tally of just 36 guests. Morning departures in the True North's adventure boats, helmed by a youthful crew of 20, could involve bird-spotting up a river system or taking in the quintessential Kimberley combo of crocodiles cruising past the boats' gunwales and rock wallabies ascending like snakes and ladders up vertical sandstone cliffs 1.8 billion years old. Back to the boat for lunch – often featuring Western Australian ingredients – before loading up the adventure boats for another on-the-water experience, maybe fishing for barramundi or casting baited mud crab pots deep into the mangrove maze of the Hunter River. Cocktails and canapés usually kick off on the back deck around 5pm, before the day once again dissolves into one of the finest sunsets. And because shoes aren't allowed to be worn on board, another relaxing constant on the True North is padding about the vessel's teak decks in bare feet.
Heading north from Broome to Wyndham, occasionally diverting to the surprisingly calm waters of the northern Indian Ocean and Timor Sea to steam overnight, most of the True North's time during the day is spent in sheltered anchorages and arcing bays.
It's a big sky and even bigger horizon seascape providing spectacular background scenery to experiences even more exciting than a morning or afternoon excursion in the adventure boats.
Deep within the island-studded Buccaneer Archipelago, the calm and sheltered waters of Talbot Bay are ambushed by another natural phenomenon unique to the Kimberley. Visiting the bay just two days after a full moon, Talbot Bay is experiencing huge – and rapid – tidal shifts of almost ten metres. We'd previously heard Chris Mirbach, True North's onboard naturalist and backup skipper explain: “In the Kimberley, the tides rule what we do,” and now, waiting to go through the famed Horizontal Falls, he's as much in awe of the afternoon's impending adventure as we are.
Caused by a shallow continental shelf extending into the Indian Ocean, Talbot Bay's massive tidal movement is squeezed through a brace of natural chasms linking otherwise flat sections of water. Waiting for our turn, we watch other True North crew and passengers speed through the rocky outcrops as thousands of litres of water surge inexorably through the narrow gap. Upon entering the chasm, it's a rollicking few seconds riding the improbable peaks and troughs of the Kimberley's greatest natural thrill ride, before exiting to a benign lagoon and then circling around to do it again.
Beyond adventure boat experiences, we also venture inland away from the Kimberley's rugged coastline. Pilot Rob negotiates a thrilling 20-minute flight up the Sale River, crisscrossing above the river's gorge, before finally flying down a terracotta canyon to land just metres from a remote waterfall and swimming hole. Another secluded spot only reached by helicopter is Eagle Falls, named by the True North team on an earlier visit, and now an isolated location for a barbecue and a relaxing afternoon of swimming. On a cooler morning, a short beach walk leads to Vansittart Bay's indigenous rock art, a highlight of an area traditionally owned by the Wunambal and Gaambera people. Protected by caves and sandstone overhangs, indigenous art works dating back tens of thousands of years still glow with creativity and spirituality.
Designed to explore the rivers and canyons of the Kimberley, the True North is uniquely able to access remote parts of the region. With a shallow draft of just 1.2 metres, skipper 'Gav' Graham steers the boat through a narrow gap in the Prince Regent River and edges the bow up to the multi-tiered Kings Cascade. From October to March, during the Kimberley's wet season, both rain and humidity peak, and the cascade's rocky terrace is awash with teeming waterfalls. During the dry season it is more subdued, and after an impromptu natural shower while sitting on the bow, we embark on a 30-minute bush walk, first scrambling up and over scrubby boulders, before negotiating a rope down to a swimming hole. A short rocky hike inland reveals more swimming holes concealed in Kings Cascades' one billion-year-old granite and sandstone landscape.
Our final day onboard is spent exploring the King George River, journeying by adventure boat for 20 kilometres up a narrow waterway framed by sandstone cliffs stacked haphazardly like a giant game of Jenga. The river's tightly arrayed canyons are scarred with the mossy blackening of wet season waterfalls, but under perfect late August skies, just a few gentle trickles hint at the natural power that will soon emerge to reinvigorate the Kimberley's seasonal cascades.