On every fishing outing with her grandmother, Aoi wonders if she will have the strength to carry on. The weather is ideal for shell fishing in the shark-infested waters of the Japanese Sea of Hegura Island. Yet Aoi, 21, still a novice, is nervous to dive in front of her more experienced grandmother. Machiko, 82, is a traditional Ama free diver, meaning "woman of the sea." She is one of the last custodians of a 2 000 years old expertise, one of harvesting abalone and the other precious shells that once had a place of honour at the emperors' table.The Ama tradition is passed down from mother to daughter but for several generations now the ice-cold waters, the scarcity of seashells and the mortal danger that represent both sharks and other fishing boats have discouraged the younger generation who is migrating to Japan's large cities.