Initally the films producers wanted to train a Great White shark but quickly realized this wasn't possible so three full-size pneumatically powered prop sharks—which the film crew nicknamed "Bruce" after Spielberg's lawyer, Bruce Ramer—were made for the production: a "sea-sled shark", a full-body prop with its belly missing that was towed with a 300 feet line, and two "platform sharks", one that moved from camera-left to -right (with its hidden left side exposing an array of pneumatic hoses), and an opposite model with its right flank uncovered.