Jaws Is About Struggling With Impotence
Let us cut straight to the chase: The shark in Jaws is a symbolic dick. Don't believe us? Take a look at the original paperback cover. Cruder than the movie's poster, the blatantly phallic shark is pointed at a nude female swimmer, presumably painted by a 13-year-old in the margins of some chemistry homework.
It says "a novel" so you don't think it's one of those specialized nudie mags.
Jaws is all about recontextualizing masculinity in the wake of the clusterfuck that was the Vietnam War. The movie's three male leads represent the splintered factions of men at that time. Quint is the grizzled vet, Hooper is a draft-dodging hippy, and Brody is the average husband and father who did his job but now has PTSD. More to the point, it's all about male impotence -- we know that Brody's tool isn't working properly because his wife needs to get him drunk to even fool around, while he'd rather obsess over shark textbooks.
"You're gonna need a bigger bottle."
Similarly, Quint is living alone in a shack not getting any, and Hooper is emasculated simply by his generally being such a bookish weenie. Enter the shark, a big swinging (swimming?) metaphorical dick, representing all of the sexual potency these men no longer possess.
From the very first scene, the theme of impotence is set up. We see a guy and a girl stripping, presumably to have sex in the ocean. Sadly, the guy's too drunk to catch up and do the deed -- and the dialogue really makes it sound like he's, uh, "quick on the trigger."