Impelled by a love of the sea and its largest fish, the elusive whale shark, marine conservationist Brad Norman has created a photo-identification system to assist its conservation. Based on a pattern-recognition method originally invented to study constellations in the night sky, the system will soon enable scores of coastal communities and thousands of individual divers to gather information about this gentle giant of the seas. The images they provide will help scientists understand its mysterious way of life and protect this charismatic species.