For full functionality of this site it is necessary to enable JavaScript. Here are the instructions how to enable JavaScript in your web browser .

I arrive on Christmas Island in the week after separating from the mother of my two children. The 10-year long relationship has run its course but my life suddenly seems like a shipwreck and I feel like going into solitary confinement.

As if those feelings of dislocation aren't enough, our guide, Tim Bull, is not promising much:

See Also Australia travel guide

"The food's atrocious, don't expect the Ritz," Bull assures me as we step off the three-hour flight from Perth, "and there's not that much to see on the island, except crabs, you'll see plenty of crabs."

As a shell-shocked Cancerian, whose astrological symbol is drawn from the giant crab Karkinos in Greek mythology, I draw a crumb of comfort from the idea of spending four days among my brethren.

"It's considered bad luck to crunch a crab," continues Bull, as we drive away from the airport and he conducts a slow-motion slalom along the road.

"As navigator and passenger you're responsible for spotting them," he adds, onerously, "and so far, I've managed to avoid a fatality on every visit for the last 15 years, so you won't let me down, will you?"

I focus my eyes on the road ahead. It is like a scene from a B-movie entitled Day of the Crustaceans. Red crabs are scuttling this way and that, and one is parked illegally in the middle of the thoroughfare.

Nor is this even during the October to January migration season. It is then that tens of millions of male and female red crabs head to coastal terraces to mate, then, 12 or 13 days later pregnant females continue their journey to the sea to release up to 100,000 eggs each. Finally, after a month growing in the ocean, their 5mm offspring return to make merry on Christmas Island.

"Watch out!" I shout as a kamikaze crab dashes into our path.


"Where?" asks Bull, urgently.

"There!" I respond helpfully, as our right wheels miss the crab by two centimetres.

It's a relief to get to The Sunset, our motel-style accommodation overlooking the sea in the Settlement, the island's principal town, without any incidents.

I unpack, pour myself a calming drink and sit down on the edge of the bed, which promptly collapses, launching red wine onto the covers and shards of broken glass across the floor.

"Don't worry," reassures hotel owner Angela Jones as I confess my crime, "it's happened before, we've been waiting for a replacement part for three months. Go and have dinner and we'll clear it all up for you."

Originally from Weston-Super-Mare, a dowdy holiday resort town on the Somerset coast of England, Jones has somehow found a home and a living here, in an Australian territory located 2600-kilometres north-west of Perth, in the midst of the Indian Ocean.

"I used to swim in mud as a girl," jokes Jones, gesturing to the glinting Indian Ocean as if to explain her relocation.

Over recent years, we've seen and heard plenty about refugees desperately seeking Christmas Island as first base to a new life in Australia, about those involuntarily incarcerated at its detention centre.

Indeed, while the Sunset has a sublime coastal location, it stands above the cliffs adjacent to Flying Fish Cove, upon which, on December 15, 2010, a fishing boat carrying 90 asylum seekers from Iran and Iraq, was smashed to pieces. Forty-eight people, including several children, were killed.

But now the island's detention centre is being closed and its other major industry, the phosphate mine, is reaching its final years of operation.

With both major sources of income on the way out, tourism is becoming crucial to the local economy. It's hoped that now the focus can shift onto the island's natural attributes and the 2000 people, including strong Malay and Chinese communities, who have made a home here.

It's Thursday night, and Bull and I join several locals and visitors for dinner at the Golden Bosun tavern, next door to the motel, as the sunset suffuses the Indian Ocean sky in mauve. The atmosphere is convivial and warm, the service smiley and the food, well, it's not the Ritz, but its tasty and good value.

"It's hard to describe how the island gets a hold of you," tourism association manager Karenn Singer tells me over dinner. "Those of us who live here just love it."

"I had 10 of the best years of my life here," adds Linda Cash, a scuba enthusiast who returns regularly from the mainland. "I was out diving every weekend."

Cash is my buddy the next morning as we set out with Japanese dive instructor Teruki Hamamata (Hama for short) to investigate Christmas Island's narrow fringing reef, a short boat ride from Flying Fish Cove.

We enter the ocean off the island's gnarly, steeply rising northern shoreline, descending beside the expansive slopes of hard coral that form Rhoda Wall. The water is warm, probably 27C, and drifting down, I'm struck by how far I can see under water, by the shifting shafts of sunlight illuminating the ocean.

A large grey whaler shark noses into view, patrolling the wall formed of corals that run the gamut of colours. Sculpted stacks spiral away from the wall and there are intermittent plate corals large enough for a royal banquet.

The reef also appears as undamaged by human contact as any I've dived on in 20 years, like a breathing organism as opposed to one struggling to survive pollution, over fishing and ocean warming.

Finning at the edge of the bottomless blue not only gives divers the impression of floating in space but wide-angle views over congregations of larger pelagic fish like tuna, barracuda and reef sharks. In the wet season, between November and March, whale sharks and manta rays arrive to feed on plankton.

Over four dives on two mornings, I see enough to put Christmas Island at the top of my favourite Australian dive sites, alongside Rowley Shoals, 300 kilometres north-west of Broome. But what gives this rocky speck the edge is its hollowed-out limestone shoreline, nudged by waters so diaphanous it could be a Greek Island.

While cave diving is often tricky, the island's subterranean caverns are easily accessed via shallow entry points. At Thunderdome cave, a simple swim beneath an overhang leads to a dark, sluicing chamber. Delving further in, we eventually surface in an ethereal grotto adorned by stalactites and stalagmites, which sparkle in the light of our torches.

Several dramatic features are accessible by land. At the Grotto, 10 minutes drive from the Settlement, we cool off in a brackish pool beneath a sunlit cavern entrance.

One dawn, we walk the 1.5 kilometre boardwalk between Lily and Ethel beaches through a landscape of limestone karsts, where hundreds of brown boobies are nesting. Unperturbed by our presence, we get Galapagos-close to several sets of handsome parents and their fluffy white chicks.

Inland at the Dales, on a 4WD tour with Lisa Preston of Indian Ocean Experiences, we walk through a rainforest full of huge Tahitian chestnut trees and criss-crossed by natural springs to a waterfall, spilling onto a rock platform like a silky drape.

At Merrial beach we kick back in a natural spa and on the east coast trek to secluded coves named Greta and Dolly after the early settlers' wives. The latter is known for its natural beauty but a recent storm has left it choked with thongs, plastic bottles and other debris, visibly distressing our island guides. At Greta Beach, I pick up an orange lifejacket and for a moment imagine it's a clue to the whereabouts of the still-missing MH370 and for another contemplate the desperation of asylum seekers for whom Christmas Island represented hope.

I do tai-chi one morning on the lawn of Tai Jin House, the former administrator's house, with Pete Choong, who has decamped from Sydney to teach Mandarin at the island school. I drink long into Saturday night with amiable locals, including the mysterious "Squirrel", who sits at the bar for hours sipping water, at the Bosun Tavern. And massage therapist Steve Watson, a former Perth paramedic, untwists my knotted muscles and encourages my newly hatched plan to return to Christmas Island to mend my shattered carapace.

"It may not be the place to find your next partner," says Watson, who has discovered his haven after decades of dealing with traumatic accidents, "but it's a good place to hang out until you're ready to."

It turns out too that our guide, Tim Bull, is full of it, deliberately tempering our expectations of the island's sights and its food.

With a Chinese community in place since it was the first settled in 1898, when phosphate mining began, authentic Sino cuisine is part of the fabric of society. We have memorable dinners on the outdoor terrace of Lucky Ho's restaurant in the Poon Saan community and at the Chinese Literary Association. Our breakfast of roti and grainy coffee, at the Halal cafe in the Malay enclave of Kampong is equally lovely.

Did I mention the crabs? Everywhere we go, they appear, as if they own the place, fixing their beady black eyes on us as if to say "watch where you're going, mate". It's not only 40 million or so of the red variety but several other types including wallaby-sized Robber crabs – so named because they'll pinch anything unsecured, in broad daylight – that look like they could have your hand off in one snip of an oversized pincer.

Strongly drawn, for reasons previously stated, to this crustacean manifestation, I perform my crab-spotting duties, with perhaps undue seriousness, given their numbers. However, after four days driving across Christmas Island, I'm happy to report that not a single shellfish is harmed in the making of this story.

TRIP NOTES

MORE INFORMATION

christmas.net.au

GETTING THERE

Virgin Australia flies to Christmas Island twice weekly from Perth, starting at $464 one-way; see virginaustralia.com.

STAYING THERE

Rooms at The Sunset start at $160 a night; see thesunset.cx.

TOURING THERE

Indian Ocean Experiences' four-hour Christmas Island Nature Tour costs $90 adults, $45 children; see indianoceanexperiences.com.au. The crab spawning event is forecast for Christmas Day in 2016.

Daniel Scott was a guest of the Christmas Island Tourist Association.

See also: Australia's top 20 best islands for a holiday

See also: Australia's second-largest island is still unknown to tourists