This snappy little Jaws rip-off is excellent "B" movie stuff.
Director Joe Dante cuts his teeth on this killer fish blood bath. The film is self mocking and in parts very funny. It even is not afraid to let school camp kids get eaten. As a batch of mutant Piranha are released into a pleasant little river. With it's low budget and puppet piranha. The film does not think of it's self as any other than a "B" movie homage. and this is where the film wins.
If you want to see a old but still good "B" movie this still stands the test of time.