Mike and Tony Petrakis are a Greek father and son team who dive for sponges off the coast of Florida. After they are robbed by crooks, Arnold and the Rhys brothers, Mike decides to take his men to the dangerous 12-mile reef to dive for more sponges. Mike suffers a fatal accident when he falls from the reef leaving Tony to carry on the business. But now he has a companion, Gwyneth Rhys.
Alternative titles: Duelo en el fondo del mar | Das Höllenriff | Storm onder zee | Tempête sous la mer | Rochedos da Morte | Duellen på havets bund | El arrecife de la muerte | Kaksintaistelu merenpohjalla | Ύφαλος 12 μιλίων | Yfalos 12 milion | Túl a korallzátonyon | Tempeste sotto i mari | 十二哩の暗礁の下に | Duell på havbunnen | Duelo no Fundo do Mar | Sub reciful de 12 mile | Dödens rev | Strid på havets botten | Коралловый риф | Sünger Avcıları | 12-Mile Reef