Swimming with the Sardine Run

Each winter the cold current pushes shoals of sardines up South Africa's east coast past Durban, and the predators follow. Dolphins by the hundred, Cape gannets raining from the sky and sharks working the edges turn the ocean into a hunting ground. Divers and snorkelers slip into the water among the dolphins and diving gannets, inside one of the ocean's great seasonal hunts. May through July is the season, when the shoals run thickest.