Exquisite Fakarava is a Unesco biosphere reserve and a pearl of French Polynesia, discovers Pamela Wade
"Don't worry about the sharks," Coco says dismissively. "Reef sharks, 1m only, pft."
So I kept on snorkelling, delighting in the balls of bait fish, the bright coral, a huge lumbering wrasse. It was only much later I realised that if the sharks were small, that meant they were a lot closer than I'd thought. Sometimes it pays to be slow on the uptake.
So nothing spoiled our perfect day out on the lagoon - and what a lagoon. From the air, Fakarava, an hour from Tahiti, is a wobbly rectangle, a thin outline of coral atoll dividing the deep blue ocean from the shaded turquoise inside it. Down on the water, skimming along in a boat, it looked vast, plenty big enough to accommodate the humpback whales that visit each year and have helped the lagoon to be designated as a Unesco biosphere reserve.
When we arrived at the tiny motu, or islet, where we were to have our picnic, we felt like the only people on the planet - and certainly the first to leave a footprint on its crushed coral sand. Pink sand, aqua sea, a drooping coconut palm: it was a cartoon cliche, but the lunch that Coco and Francois laid out for us was a real feast. Steak barbecued over an open fire, fresh raw tuna marinated in coconut milk, salad, French bread and fruit, with a glass of chilled rosé: delicious, and even better eaten in the rustling shade of a palm tree watching ripples lap onto the sand.