There is not a drop of fresh water on Jaco Island. It lies six hundred metres off the eastern tip of Timor-Leste, and it is coral through and through. Reef limestone grew underwater here and was pushed up into the daylight, where the Australian plate drives under the Banda arc and is still lifting old seabed into terraces. Limestone drains. Rain sinks straight through it and comes out below the sea, which is the plain reason the island has never been settled. Fataluku custom made that permanent. The ground is tei, withheld by the ancestors, and traditionally only ritual specialists could set foot on it. Day visits are accepted now, and the village at Valu runs the crossings, but the core of the rule has not moved: nothing may be built, and nobody sleeps on the island.
The boats lie drawn up on the sand at Valu Sere. The crossing takes fifteen minutes, and the same boatman reads the swell to decide when he will come back for you. You wade in from white sand and the reef is on you at once, parrotfish and coral in water barely deep enough to swim in, before the shelf tips away into blue. Turtles are ordinary company, and these corals were spared the fishing and anchoring that thinned reefs elsewhere in the region. Along the island's edge the white sand runs into black fossil coral, sharp as knives. Across the channel are the forested cape of the mainland and the mountains behind it: the country coming to an end. Between October and December hundreds of pygmy blue whales push south through the deep strait off the point, on their way to Australia. You carry every drop you will drink, because the island has none, and everyone is back on the mainland by dusk. The Fataluku call this place the head. In their telling Timor is a crocodile that lay down in the sea and turned itself into land for the boy who once saved it, its ridged back the mountains — and the head is here, where the sand stops.