How many mechanical sharks played Jaws?

3

Three full-size pneumatically powered prop sharks were made for the production: a "sea-sled shark", a full bodied prop with its belly missing that was towed with a 300′ (roughly 100 m) line, and two 'platform sharks', one that moved from camera-left to -right (with its hidden side completely exposing a wide array of pneumatic hoses), and an opposite model with its right flank uncovered.[20] The sharks were designed by art director Joe Alves during the fall of 1973.3