Chelonia PODs have revolutionised the way we study cetaceans in the wild. These fully automated passive acoustic monitoring instruments detect porpoises, dolphins and other toothed whales (except sperm whales) by recognising the trains of echo-location sounds they produce to detect their prey, orientate and interact. Standard PODs can be deployed to at least 100 metres, while the deep sea version is designed for deployments to at least 2 km. Over 3600 PODs have been deployed worldwide.