Pericolo Negli Abissi (1977)

Pearl fishermen from Red Sea, scuba harpooners from Polinesia, Japanese diver women expose themselves every day to attacks by sharks infesting their waters. Fishermen of abalone from Mexican California work in waters where they often meet the killer whale, the biggest predator of all the oceans. Scuba divers collecting the black coral at the Hawaii do their job 80 m deep, where a bad encounter and a risk of an embolism are continuous. Even bigger is the risk the coral fishermen from Sardinia take, when they reach 120 m deep using special respiratory mixtures. Then there're also the scuba diver geologists trying to study underwater volcanic eruptions and the biologists who approach dangerous animals