Erricos Andreou - To agistri AKA The Hook (1976)

Kostas is an all-powerful tycoon, in love with his beautiful wife, Iro, who, however, is cheating on him with a young playboy, Nikos. The two lovers are planning to kill Kostas, and believe that the opportunity arises during a yachting regatta, where the crime can appear as an accident. Nikos, however, falls into the sea, and his body is never found. The police investigating the cause of the accident don’t believe the claims of Nikos’ fiancée that her fiancé was murdered. As it turns out, Kostas was aware of his wife and Nikos’ plans, and the disappearance of the latter was his idea for revenge. Nevertheless, the conflict of the married couple will be fatal for everyone.