The crew nicknamed the mechanical shark used in Jaws “Bruce.” The name honored Bruce Ramer, Steven Spielberg's lawyer, rather than referring to a character or a real shark.
The production built three full-size, pneumatically powered shark props after the filmmakers realized that training a great white for the movie was impossible. One was a sea-sled shark, designed to be towed through the water on a 300-foot line. Two platform sharks were built for side views, with each exposing different hidden mechanisms so the camera could photograph the shark from either direction.
The sharks were designed by Joe Alves and constructed under the supervision of mechanical-effects expert Bob Mattey. Up to 14 operators were needed to control a model's moving parts. Their unreliable performance contributed to the film's famously difficult production and encouraged Spielberg to suggest the shark through music, reactions, and glimpses rather than showing it constantly.
“Bruce” is sometimes confused with the shark character named Bruce in Finding Nemo. That later animated character is also a great white, but the name is a reference to the Jaws production nickname.