By day, Galathea Bay, a crescent of sand in the wild frontier of Great Nicobar Island, is bathed in the shifting blues and emeralds of the Indian Ocean. Behind it rise dense tropical forests, alive with flora and fauna found nowhere else. Clear streams and waterfalls slice through the green, emptying themselves into mangrove-lined creeks where saltwater crocodiles bask in quiet estuaries. February is the dry season here, and the air hangs hot and humid. But, by night, the beach turns cool, dark and hushed, the moonlight casting a silver glow across the sea. From the waters emerges an immense shape, dragging itself ashore. She’s a leatherback turtle, two metres long, weighing over 400 kg, one of the largest sea turtles on Earth.
