in early june 1974, the boston local of aftra (american federation of television and radio artists) sent a message, to all its local members, informing them that universal pictures was filming the motion picture "jaws", on martha's vineyard and they were looking for extras. harrington packed his car and headed for the island. a day into his 'extra' work, first assistant director tom joyner asked jim to do some minor stunt work. the previous day, they had filmed a scene where two fishermen tried to catch the shark by attaching a chunk of meat to a hook and chain and then tying it to the end of a pier. the script called for the shark to snatch the bait and then, with hook in mouth, rip the dock in half, and take one of the two men on a 'nantucket sleigh ride'. after being pulled by the shark for some distance, the fisherman was to roll back into the water, swim for the safety and scramble up the other half of the pier. as he's doing this, the shark pulls a u-turn and heads in his direction. the original actor had left martha's vineyard and director steven spielberg needed to shoot some additional footage. harrington was enlisted and spent most of the next day in front of the camera, performing parts of that scene.