" jaws " is a rare film that grabs your attention before it shows you a single image on screen . the movie opens with blackness , and only distant , alien-like underwater sounds . then it comes , the first ominous bars of composer john williams' now infamous score . dah-dum . from there , director steven spielberg wastes no time , taking us into the water on a midnight swim with a beautiful girl that turns deadly . right away he lets us know how vulnerable we all are floating in the ocean , and once " jaws " has attacked , it never relinquishes its grip . perhaps what is most outstanding about " jaws " is how spielberg builds the movie . he works it like a theatrical production , with a first act and a second act . unlike so many modern filmmakers , he has a great deal of restraint , and refuses to show us the shark until the middle of the second act . until then , he merely suggests its presence with creepy , subjective underwater shots and williams' music . he's building the tension bit by bit , so when it comes time for the climax , the shark's arrival is truly terrifying . he doesn't let us get bored with the imagery . the first act opens with police chief martin brody ( roy scheider ) , a new york cop who has taken an easy , peaceful job running the police station on amity island , a fictitious new england resort town where there hasn't been a murder or a gun fired in 25 years . the island is shaken up by several vicious great white shark attacks right before the fourth of july , and the mayor , larry vaughn ( murray hamilton ) , doesn't want to shut down the beaches because the island is reliant on summer tourist money . brody is joined by matt hooper ( richard dreyfuss ) , a young , ambitious shark expert from the marine institute . hooper is as fascinated by the shark as he is determined to help brody stop it -- his knowledge about the exact workings of the shark ( " it's a perfect engine , an eating machine " ) make it that much more terrifying . when vaughn finally relents , hooper and brody join a crusty old shark killer named quint ( robert shaw ) on his decrepit boat , the orca , to search for the shark . the entire second act takes place on the orca as the three men hunt the shark , and inevitably , are hunted by it . " jaws " is a thriller with a keen sense of humor and an incredible sense of pacing , tension , and horror . it is like ten movies all rolled into one , and it's no wonder it took america by storm in the summer of 1975 , taking in enough money to crown it the box office champ of all time ( until it was unceremoniously dethroned in 1977 by " star wars " ) . even today , fascination with this film is on par with hitchcock's " psycho , " and it never seems to age . although grand new technology exists that makes the technical sequences , including several mechanical sharks , obsolete , none of it could improve the film because it only would lead to overkill . the technical limitations faced by spielberg in 1975 may have actually produced a better film because it forced him to rely on traditional cinematic elements like pacing , characterization , sharp editing , and creative photography , instead of simply dousing the audience with digital shark effects . scheider , dreyfuss , and shaw were known actors at the time " jaws " was made , but none of them had the draw of a robert redford or paul newman . nevertheless , this film guaranteed them all successful careers because each gave an outstanding performance and refused to be overshadowed by the shark . scheider hits just the right notes as a sympathetic husband and father caught in the political quagmire of doing what's right and going against the entire town . " it's your first summer here , you know , " mayor vaughn warns him . dreyfuss , who had previously been seen in " american graffiti " ( 1973 ) and " the apprenticeship of duddy kravitz " ( 1974 ) gives a surprisingly mature , complex performance for someone who had literally only played kids and teenagers . however , most outstanding is the gnarled performance by robert shaw as the movie's captain ahab , a performance sorely overlooked by the academy awards . bordering of parody , shaw plays quint as a grizzled old loner whose machismo borders on masochism . he's slightly deranged , and shaw's performance is almost a caricature . however , there is one scene late in the film , when he and brody and hooper are below deck on the orca comparing scars . quint is drawn into telling the story of his experiences aboard the u . s . s . indianapolis , a navy ship in world war ii that was sunk by the japanese . his tale of floating in the water for more than a week with over 1 , 000 other men while swarms of sharks slowly devoured them them is actually more hair-raising than anything spielberg put on screen . shaw delivers the story in one long take , and it is the best acting in the film . of course , we can't leave out the shark itself ; with its black eyes , endless rows of teeth , and insatiable urge to eat , it is basically the epitome of all mankind's fears about what is unknown and threatening in nature . a shark is such a perfect nemesis it is real -- having survived sinch the dinosaurs , great whites do exist , they can be as large as the shark in " jaws , " and they are a threat . every one of spielberg's subjective underwater shots makes us feel queasy because lets us see how we look to the shark : a bunch of writihing , dangling , completely unprotected legs just ready to be chomped into . the shark in " jaws " was actually a combination of actual footage and five different mechanical sharks ( all nicknamed " bruce " by the crew ) built to be shot from different angles . many have forgotten , but " jaws " was a sort of precursor to " waterworld " ( 1995 ) , a movie's who soggy production and cost overruns had universal studios worried about a bomb . but , as we can see now , spielberg overcame all the obstacles , and delivered one of the finest primal scare-thrillers ever to come out of hollywood .