The Bay of Virgins appears deserted. A handful of rocky outcrops, unmistakably phallic, dominate its lonely black shore, and rearing behind is a fortress of spires, volcanic blocks and fang-tooth ranges. We're as likely to find dinosaurs as virgins ashore.
Our little boat bobs wildly as we approach a sea-cliff flanking the bay. We wait for the next muffled explosion inside a nearby blowhole to let loose a spume, adjust snorkels and fins, and drop over the side.
Until now we've been snorkelling on calm coral reefs fringing the Tuamotu Archipelago, a smattering of atolls and islands roughly the size of western Europe within the far-flung constellation of French Polynesia. The islands appear on the horizon as bristles of coconut palms stuck in white sand, barely high enough to clear the opalescent ocean, the water bath-tub warm, the reefs teeming with fish.
It's taken another couple of days at full throttle to reach the mysterious Bay of Virgins on Fatu Hiva, the southernmost of the Marquesas Islands. There's an edge-of-the-Earth feeling here, and it's not just my overheated imagination. The Marquesas are among the most remote island groups in the world - 1,400 kilometres from the Tahitian port of Papeete where we embarked, and another 4800 kilometres from the next land mass, the faraway west coast of Mexico. Our expedition to the coral-atoll Tuamotus and the volcanic Marquesas is a study of polar opposites in the tropics.
There's no reef around the Marquesas - "it's the big blue, nothing for 500 metres, maybe deeper," says our French expedition leader, Louis Justin. The sensation of slipping off the inflatable Zodiac into this cool fathomless void is akin to jumping off a tall building: a moment of exhilaration, then vertiginous terror. There's nothing but ink-blue infinity, the sound of my own panicked breathing and the delicious fear of the unknown.
Expeditions throughout history have been journeys into the unknown, in often perilous pursuit of adventure, knowledge, territory, treasure. In a fashion, so it is on our 10-night voyage into the remote reaches of French Polynesia aboard one of Silversea's three expedition ships, the 120-passenger Silver Discoverer - though the exploration is done in tremendous style and comfort, and there's far more pleasure than peril (overeating and sunburn).
Of course Magellan and Columbus would not recognise days like this as expeditionary. It starts at dawn with a stretch class under a bowl of blue sky with Natasha Eksteen, a South African fitness trainer and triathlete; fresh juice, goat's cheese omelette and good coffee for breakfast by the pool; and the deck-side approach of Fatu Hiva, or Jurassic Park as I come to think of it.
As soon as we anchor in the Bay of Virgins, we're clambering into one of Silver Discoverer's dozen Zodiacs for the short ride to shore. Possibly the entire village of Hanavave is waiting for us with a welcome chant more fierce than friendly. We receive double-cheek kisses and gifts of cowrie-shell necklaces and lei strung tightly with frangipani, herbs and tiarés, the white, heavily scented national flower. There are ukuleles - always, there are ukuleles - and women of all ages wearing floral crowns and bright sarongs that tremble suggestively as they dance in the traditional, swivel-hipped way. "The feet make a figure-eight, and the 'ips they follow," one woman explains to me, her midriff rolling like the surf. Beside her, my best efforts resemble a belly-flop.
After the dancing we peel off for a stroll to watch birds or a more strenuous hike into the steamy, silent mountains, high enough to look down on the mothership and the big blue into which we'll plunge soon.
An hour after our deep-sea snorkel we're back on board, showered and drinking rum punch from coconut shells on a pool deck draped with palm fronds. It's barbecue night, and some of us wear our lei, which are now as intoxicating in the heat as the cocktails, and there's fish grilling and lobster chilling and a roast suckling pig on the table. We've known our fellow cruisers - mainly Australians, Americans and Germans - long enough now that no one feels too shy to join a conga line and dance by the pool when Lou the ebullient DJ launches into remixed disco hits. Much later we lie on yoga mats on the open top deck and listen to Tua Pittman, a charismatic Cook Islander and member of the expedition team, as he reads the vast celestial map overhead, in the way that Polynesian navigators have done for generations.
The ship's routines quickly become familiar - meal times, briefings, lectures, cocktail hour, night- time sailing - but otherwise every day unfolds as a fresh series of adventures in Zodiacs with a crew and expedition team eager to turn a great day into an even better one. We follow the itinerary, but there's a refreshing willingness to respond to the unpredictable - the weather, the tides, the chance sighting of manta rays. This allows an unscheduled and sublime half-day on a deserted island, for example, and a thrilling session of drift snorkelling in a passage funnelling the ocean (and fish, sharks and snorkellers) into a doughnut-shaped atoll.
We arrive in Rangiroa - "the big sky" in Tuamotuan - late on our first morning at sea. As soon as we anchor we're off in our Zodiacs, some heading to a pearl farm to see how the region's famous black pearls are grown, others to snorkel and dive inside the largest atoll in the archipelago. Inside is a vast turquoise lagoon - 67 kilometres long, 26 wide - mottled with reefs and 400 islandsand teeming with marine life. As soon as we slip overboard we're surrounded by a school of snapper that approaches en masse, then shatters like glass. Silver Discoverer carries a fully equipped dive boat and staff on expeditions to some of the world's best dive sites, and there's a handful of divers on this trip. I'm surprised when I quiz the New Zealand dive master, "Scuba Steve" Traynor, about his favourite spots and he nominates today's dive in Tiputa Pass, which sees divers clinging to the sea-wall beside schooling white-tip reef sharks, stationary but swimming hard against the current rushing into Rangiroa.
With so many Zodiac-led diversions, there's not much reason to stay indoors or tax the charming butlers assigned to each room. My room on deck four is compact and comfortable, with clever use of space- enhancing mirrors, honey-coloured joinery, cream wallpaper and gold-and-navy accents. It's furnished with a queen bed, storage for two, a couple of armchairs, a tiny writing desk, a neat, marble-clad bathroom and a window (suites on upper decks have balconies). Public spaces, likewise, are compact and unfussy. Dinner is served in the formal third-deck restaurant or outside by the pool, where steak and seafood are grilled DIY on "hot-rock" plates at the table.
Ours is one of more than a dozen "wellness" cruises that give guests access to group and private sessions with a trio of health professionals: fitness instructor, yoga teacher and nutritionist. "Food is very important on cruises, but we feel that culinary nutrition on board - creating food that is delicious, satisfying and also very healthy - is becoming more important," says Italian nutritionist Dalila Roglieri. She's kept busy designing personalised nutrition plans for guests, and she works with Silver Discoverer's chef and kitchen staff to make at least four extra "wellness" dishes each night and a range of "superfood" dishes and juices for breakfast and lunch. She also nips and tucks the regular, mostly Mediterranean menus to reduce fat, sugar and portion sizes and add more grains and vegetables.
I'm saluting the sun in a top-deck yoga class when we anchor next morning outside Ahe atoll, a long stretch of palms hovering at sea level. A crowd is waiting for us at the dock with lei and kisses, and people are setting up tarpaulins over tables of local delicacies - black-lip pearl meat in lemon juice and 101 ways with coconut (fresh, fermented, sprouted, thickened, sweetened and more). The local policeman arrives with his ukulele and leads the village in song and dance, and a stand-in for the mayor laments that ours is the first cruise ship to visit the village in 20 years. Farmed pearls and coconuts are the only sources of income here. I chat with Mareta Tetuamanuhiri about pearl-farming and tattoos. Born in Seattle with a Polynesian father, she moved from Tahiti to Ahe, population about 550, a year ago. Like many young women of Polynesian heritage, she has a beautiful back tattoo from shoulder to hip full of symbols representing her ancestors.
On the neighbouring atoll of Manihi, even more people turn out on a sweltering afternoon to greet us with smiles and woven palm hats with long fronds cascading comically from the brim - the effect israther like wearing a tree. Ladies in technicoloured muumuus serve fresh coconuts and sell black pearls, and there's more dancing - under-eights and ukulele tunes are a winning combination. Later we snorkel with reef sharks and surgeonfish on a sloping lawn of coral close to the village. The spine at the base of the surgeonfish tail, says our resident marine biologist, Patrick Demus, was once used for tattooing.
Demus is part of a 10-strong expedition team of field-tested scientists just as adept at manoeuvring Zodiacs safely into atolls as they are at identifying species. Among them is a photographer-filmmaker, Richard Sidey, who holds workshops and captures the voyage on drone footage and video. The scientific crew covers botany, marine biology, anthropology, geology, history and Polynesian voyaging, which makes them diverting storytellers during days at sea and great dinner companions. Tua Pittman tells fascinating stories about month-long voyages in Polynesian vakas - twin-hulled ocean canoes, navigated only by traditional means - memorising the rising and setting positions of more than 150 stars, reading the flight patterns of birds and ocean swells, the colour of clouds. No GPS, no radio, no instruments.
Thirty years ago there was only one pwo, or master navigator, still alive - the skills were among many cultural practices banned or lost after Europeans and missionaries arrived. Mau Piaulug, of Satawal in the Caroline Islands, was already middle-aged when the Polynesian Voyaging Society encouraged him to teach a new generation, and Pittman - who can trace his Polynesian genealogy for 10 generations - was among them. In recognition of his expertise, he was initiated as a pwo in 2008. "Now it's my role to teach my children and the next generation," he says. "For 3000 years Polynesians have been the world's greatest seafarers. What I'm doing is about the continuity of Polynesian culture."
At least one tradition was, mercifully, discontinued long ago. In the jungle at Puamau, on the Marquesan island of Hiva Oa, we view a partly excavated mea'e, a series of platforms used until the 19th century during human sacrifices and death rituals. It's crowned by the largest stone tiki - enigmatic carved figures - outside Rapa Nui, aka Easter Island, where they are known as moai. We hang on the grisly details outlined by Alexandra Edwards, a Rapa Nui archaeological researcher and member of the expedition team. First the deified priest would eat the eyes of the poor unfortunate unlucky enough to be rounded up and killed after the conch-shell alarm was sounded. Next the heart was removed, then the palms were eaten, then the soles of the feet, and the bones were thrown in a pit atop a rocky spire - Edwards points high above us. The bones of those lucky enough to die of other causes were wrapped in bark cloth and left there, too, after their tattoos - regarded as a link to the land of the living - were erased by rubbing coconut oil into the skin for months. It's hot and humid in the clearing among these strange stone figures, and the stench of something recently deceased wafts over us. "There's mana here," says Edwards, using the Polynesian word that loosely translates as power or supernatural spirit.
A different sort of spirit animates the House of Pleasure in the town of Atuona, on the other side of the island. It's a reconstruction of the home occupied by the French painter Paul Gauguin, who settled here in 1901. He'd escaped his family and financial problems in Europe and sailed to Tahiti in 1891, vowing to escape "everything that is artificial and conventional". He died in Atuona two years after arriving - alcoholic, possibly syphilitic, penniless - with a body of bold, experimental work inspired by his exile in paradise and a string of barely pubescent Polynesian lovers. Beside the House of Pleasure, its creepiness enhanced by a wax figure of the artist, is the Paul Gauguin Cultural Centre, full of reproductions of his works. Much of it depicts voluptuous young women dressed only
in flowers, and heroic self-portraits. Narcissistic pedophile or brilliant exile? Graveside is as good a place as any to consider a life. Gauguin's is a humble pile of volcanic stones set under a frangipani tree in a cemetery overlooking the harbour. Someone has placed a small rubber duck beside the headstone.
By the time of Gauguin's death the population of the Marquesas had dwindled to about 2000, from an estimated 100,000 in the 16th century. The islanders were ravaged by diseases passed on by Europeans, their cultural practices banned or discouraged by missionaries and French colonists, who assumed control in 1842. It wasn't until the late 1970s that Marquesan identity was revived. On the island of Ua Pou I meet Heato Teikiehuupoko, president of the island's tourism committee; his father, Georges, set in motion the slow revival of traditional practices - song, dance, tattooing, carving and teaching Marquesan language in schools - with encouragement from an unorthodox French bishop, Hervé-Maria Le Cléac'h. "We can now teach Marquesan dance at schools, and we're trying to share a sense of identity with the next generation," says Heato. "Our culture is still alive."
There's fierce drumming when we disembark on Ua Pou, and we walk through the neat streets of Hakahau lined with ripening mangoes and breadfruit, bougainvillea and hibiscus, past a Catholic church and pétanque court to an ancient platform excavated in a steamy jungle clearing. Seven young tattooed warriors wearing feathers, necklaces of horn and tooth and little else throw themselves into ferocious chants and dances of ancestral rivalry and battle. By the time they finish what Heato calls "the dance of seduction" we're all breathless.
From the Marquesas we head back to the coral reefs of the Tuamotu, past islands with too many vowels (Eiao, Hereheretue, Ua Pu). The ill-fated Mururoa, used by the French for 30 years of nuclear testing, is located in the southern reaches of the archipelago. At Tahanea, our Zodiacs slip into a lagoon of such startling clarity we decide its colour can be described only as "ridiculous blue". We splash ashore at an island inhabited only by fist-sized hermit crabs, and spend the morning wandering like castaways and swimming with parrot fish. At an island inside nearby Motutunga atoll we poke around a couple of abandoned shacks and snorkel in the shallows, and emerge to find the crew has set up a sunset bar and ice-cream stall on the beach.
Next morning there are more kisses, more dancing and a lot more flowers at our final stop on the wonderfully named atoll of Fakarava. I sit in the sand and help a posse of women thread tiarés and bougainvillea on headpieces, and chat with two sisters: one whose name means nesting dove, the other whose name means human sacrifice. Really? "It's an ancestor thing," she shrugs. They're training to start their own business, a café and gallery in town.
I think of the Fakarava sisters as we're heading back to Papeete that afternoon. It's customary to return a lei to the earth that it came from, and I hope the sea is the next best thing. So I stand alone on a back deck and unthread tiaré flowers by the handful. They settle white on the ocean for a moment, then they're gone.