SMALL PRINT:ONE MORNING in the 1980s, my younger brother and I shuffled down the stairs, bleary-eyed and slightly shell-shocked. As we mournfully munched our cereal, we wondered who'd confess first. "I thought he was going to come through the wall!" he finally wailed. I nodded in solemn agreement. "I was sure he was under my bed." Twelve hours previously we had seen Jawsfor the first time.

At nine, the fact that Jawswas a masterpiece also went over my head. It was made during Steven Spielberg's finest decade in various film production roles, which began with Jaws(as director) in 1975, followed by Close Encounters of the Third Kind, Raiders of the Lost Ark, ET, Poltergeist, Gremlins, The Gooniesand Back to the Future. On release, Jawswas an unprecedented success, becoming the highest-grossing film in the US, until Star Warscame along two years later.

The studio believed that big names would distract from the story, so several actors were mooted but turned down for the film. Robert Duvall and Charlton Heston were rumoured for Brody’s part (Heston never forgave Spielberg when he didn’t get it). Lee Marvin said no to playing Quint and both Jeff Bridges and Jon Voight auditioned for the part of Hooper.

The chemistry between the trio who eventually played the roles of Quint (Robert Shaw), Brody (Roy Scheider) – pictured above in the film – and Hooper (Richard Dreyfus) is nail-biting to watch. Shaw and Dreyfus didn’t get on, and fought constantly on set, which added to the claustrophobic tension on the boat.

The fourth performance of note is that of the shark, fondly nicknamed Bruce (after Spielberg’s lawyer). Like most directors dabbling with horror, Spielberg recognised that the possibilities in an audience’s imagination would be far more effective than anything he created visually. As a result, it’s an hour into the film before we get to see the actual shark. The first sighting arrives via an understated moment, as Brody shovels “chum” bait into the water. It’s also punctuated by one of the most memorable lines in cinema lore; “You’re gonna need a bigger boat” wasn’t in the script and was famously improvised by Scheider’s Brody.

Several key scenes were shot underwater – at sea and in customised tanks – and Spielberg shot many scenes at waist level to give the audience’s point of view. He also used the camera to show the shark’s eye-view, but this was due to delays caused by recurring faults with the mechanical shark rather than arty aesthetics. What remains the most memorable element of the film is not sinewy, floating limbs or Ben Gardner’s disembodied head, but John Williams’s terrifying score.

Spielberg initially had doubts about it (it went on to win an Oscar) but later admitted that the film wouldn’t have been as successful without it. It’s an intelligent blockbuster that still has bite.

Jawsscreens as part of the Spielberg Season at the IFI, Dublin tonight at 6.40pm. ifi.ie