The first underwater POV shot of Chrissie swimming on the surface is accompanied on the soundtrack by a rippling harp effect underscored by the menacing throb of a cello. In film scoring the first instrument is commonly associated with the sea: if you stroke its strings to create a glissando, it sounds like the rush of water. The music has a briefly ethereal quality to it, emphasising the notion that on entering the sea the girl has transformed into a mythical siren. Her body is seen in silhouette swimming diagonally across the screen and interposing itself between the viewer and the moon. The languorous stroke of the girl as seen from below is slightly at odds with the less elegant crawl we see in the next shot from the surface, suggesting that the images are of the two different performers Susan Backlinie and Denise Chesire.
The iconic image recalls the silhouettes of the female form that title designer Maurice Binder used for the Connery and Moore Bond movies - in particular, Thunderball where lithe naked girls perform underwater acrobatics against a blue background. The technique that Binder employed was a classic burlesque tease that suggested nudity without actually showing it. In Jaws the day for night post-production preserves the actress's modesty and hides what - according to movie legend - was explicitly on display in the original rushes.
When there is a cut to a medium head and shoulders shot of Chrissie treading water, we notice for the first time that she is wearing gypsy earrings. It's a curious detail: is it there to hint at the free-spirited wild child nature of the girl, or is it something for the light to play on? If you look closely at the classic image of Chrissie's death that was used for the movie's publicity you can just about make out one of the silvery hoops on her left ear.
