Turtles are masters of navigation. They live their entire lives in the sea, coming ashore once in two or three years, and then only at night for two or three hours to nest. Then the hatchlings emerge, tiny creatures half the size of your palm, and venture into the ocean. Years later, they come back to their birth shore to nest.The enigma surrounding the lives of turtles appealed to Kartik Shanker. As a student in Madras Christian College in late 1980s, he and his friends participated in tur