Piranha II: The Spawning, is a 1982 American-Dutch-Italian horror film directed by James Cameron in his theatrical feature film directorial debut. Part of the Piranha film series, it is the sequel to the film Piranha (1978) directed by Joe Dante. (Wikipedia)
Considering this was directed by a guy whose only film at the time was Piranha II: The Spawning. It seems like a miracle.