Naturally, nobody knew two years prior to release just how important it would become (smashing all previous box-office takings that summer and single-handedly creating the summer blockbuster); in fact, pretty much all concerned thought it was going to be a disaster, not least because of the oft-quoted stories concerning the completely unreliable shark effect, which Spielberg himself called 'the great white turd'.
I watched it again over the weekend and was amazed how well it all held up. Really, the shark isn't that bad - and of course, Spielberg's genius was to rack up that tension a good hour before we even see the beast.
There's lots of well-worn trivia about the mechanical creature, as well as John Williams' seminal score, but I thought it would be fun to jot down some facts less well-known.
Here's my choice.
Ten Things You (Possibly) Didn't Know About Jaws
1. Blink and you'll miss it: As we approach the first night on the Orca, watch carefully and you'll see a shooting star rip across the sky, right behind Roy Scheider. (I'd never seen this until I watched the remastered version at the weekend - I read into it, wondering if it was a post-production effect, but apparently it is genuine.)
2. The role of Quint (Robert Shaw) was originally to be played by Lee Marvin, at least if Spielberg had got his way. Marvin turned the offer down, saying he'd 'rather go fishing'.
3. Chief Brody's son narrowly escapes getting chomped when the shark enters the shallow waters of Amity beach. He's held in hospital for the night, even though the nurse says he's only suffering 'mild shock'.
It's only when you see the sequence that didn't make the final cut that you realise the extent of the boy's trauma; the unintended victim of the shark attack puts himself in the path of the shark to save the child, holding the boy out of the way while the great white eats the man alive. Spielberg decided the scene was too gory and in 'poor taste'.
(The scene is available on the Region 2 remastered DVD release).
4. The movie is cited as the single biggest cause for a historic downturn in coastal vacations during 1975-76.
5. Spielberg was careful to avoid using the colour red (you'll not see anyone wearing it), so as to maximise the impact of blood on-screen when the shark attacks.
6. Quint's boat, The Orca, was so unseaworthy when production started - thanks to it's unfeasibly top-heavy design - that production staff had to quickly locate lead for ballast from the town of Martha's Vineyard, where Jaws was being shot. All they could find was lead lining due to go into a dentist's X-Ray room, which was rented for a high premium on a daily basis.
7. Author Peter Benchley disagreed about the ending of the movie so persistently, he was thrown off-set. His conclusion leant closer to that of Moby Dick, but Spielberg wanted a more cinematic 'punch'. (Benchley now concedes the director's ending is the better of the two.)
9. One of the biggest shocks in the movie comes when a severed head rolls out of a wrecked boat. Unsatisfied with the initial audience screams, Spielberg re-shot the sequence in his editor's small home swimming pool, using a gallon of milk to muddy the water because he wanted his audience to 'scream louder'. It worked.
10. The bizarre, feral noise you hear as the shark carcass sinks to the bed of the ocean is the same effect used when the truck goes off the edge of the roadside during the climax of Spielberg's earlier Duel (1971).