I am paddling amid a group of five blacktip sharks which are cutting a smooth path through the warm, shallow ocean. It's my first encounter with the legendary underwater beasts – each at least two metres long – but their indifference to my presence is calming.
We spotted the sharks on the very first day of a week-long jaunt by catamaran around Tahiti and nearby Moorea, the inaugural voyage of Pacifique Adventures, a new company run by French duo Dimitri Zoëllin (the skipper) and Simon Maillard (the chef). After years working on big boats and with large companies, they've set up this bespoke service, so you can decide where you want to sail and how long you want to moor in any one place.
Chartering a boat also allows you to pick your preferred destinations. If you've come for the surf, you should head for Teahupoo on the south-west side of Tahiti, home to some of the world's most challenging reef surfing. If visiting pearl and vanilla farms is more your thing, go north to Bora Bora and Huahine.
Tahiti and her islands, a sprinkling of more than 60 tiny volcanic isles and coral atolls, lie in the southern Pacific Ocean between North and South America, Asia and Australia. Over the years they have played host to seafaring adventurers from every corner of the earth, a vital pit stop between continental land masses. Ultimately, it was the French who stayed here: it remains a semi-autonomous French territory and its inhabitants are French citizens.
Perhaps it is this heritage that deters British visitors, who usually plump for the English-speaking Cook Islands. It could also be the arduous journey – I flew first to Paris, then to Los Angeles, a 12-hour flight, followed by another eight-hour haul to Tahiti.
A further deterrent is the prohibitive cost of this once-in-a-lifetime destination. But chartering a boat is more economical than one of the many large and impersonal hotels. Each day on the boat will cost about £180 per person all in, whereas you'll be lucky to find a half-decent hotel for less than that a night, to which you add £2 a throw for a can of Coca-Cola, £12 for a cocktail, a tenner or so for a basic lunch and whatever your wallet can bear for dinner. And bump that up with the price of getting from island to island.
The Lagoon 440 catamaran was comfortable and well appointed. Each of the four double cabins had a private shower room, toilet and air conditioning, much needed in the hot hours of the early afternoon. The cabins were all below deck; upstairs there was a lounge and dining area, with another dining table set outside for mealtimes. Out of a tiny kitchen, Simon prepared delicious food, including seared hunks of spiced tuna and avocado salad, mango mousse, indulgent chocolate fondant and French cheeses.
There is also ample space on deck for relaxing and sunbathing. But there are other diversions, too: visit Moorea's pineapple and grapefruit plantations, or a pearl shop to find out about the South Pacific's famous export. I even took a trip by pirogue, a Polynesian kayak, to visit the huddle of motus – tiny uninhabited islands – at Moorea's north-westerly tip.
But some of the most enjoyable activities are snorkelling and diving: spot yellow box fish navigating the reef's intricate caves, and marvel at the spines of a blood-red sea urchin gently swaying with the current. Huge clumps of violet-coloured coral, and fish in shades of pink and yellow no human has yet succeeded in recreating. I missed out on the whales and dolphins, though a lone turtle swam past one day and there were frequent sightings of manta rays on the ocean's sandy floor. It's the view below the waves that is Tahiti's most compelling attraction.
How to get there
Sophie Morris travelled to Tahiti as a guest of Rip Curl (ripcurl.com). You can fly to Papeete from Paris via Los Angeles with Air Tahiti Nui (0870 066 2050; airtahitinui. com), Los Angeles with Virgin Atlantic (08705 747 747; virgin-atlantic.com) or British Airways (0844 493 0787; ba.com) then on to Papeete with Air Tahiti Nui.
Charter a Lagoon 440, sleeping eight, with Pacifique Adventures (pacifiqueadventures.com) for €1,295 a day, plus €30 per person per day for all food and drinks.