The moment when Hooper visits Brody household with some wine as a souvenir. Martin, fed up with the whole shark problem, starts filling his pint with the wine despite Hooper's protests that he should let it breathe. Then he gives Ellen and Hooper the smallest amount imaginable.
And it's the red wine, even though they're having fish.
"My husband tells me you're in sharks."
When Quint sees the shark cage, he doubts its reliability, saying "you go in the cage. Cage goes in the water. Shark's in the water," then smiles and starts singing "farewell and adieu to you fair Spanish ladies! Farewell and adieu, you ladies of Spain!"
At one point Quint crushes a beer can in his hand, and Hooper responds by doing the same thing with a styrofoam cup.
The vandalization itself, with a spray-painted shark fin and a speech balloon coming from the beach bunny: "Help, shark!"
And the hint that these were particularly well-researched vandals, drawing the fin in correct proportion to the woman.
Might just be a case of the casting not matching the script, but I always found it amusing how everyone treats Hooper like he's a fresh out of college kid. Dude has gray in his beard.
Dreyfuss was 27 when the film was released which isn't beyond college age depending on what degree is being pursued, especially in the sciences. Also, compared to Shaw and Scheider, he was relatively young. It is true, however, that this was a case of casting not matching the script as the script was adjusted for Dreyfuss.
And people can start to go grey in even their late teens.
Brody and his wife are arguing over whether they should let Michael play in the water.
Ellen: Martin, it's his birthday tomorrow!
Brody: I don't want him out on the water!
Ellen: He's not in the water! He's on a boat. I don't think he'll ever go in the water after what happened.
''*Flips through a book filled with illustrations of sharks attacking boats and eating people*
Ellen: Michael! Did you hear your father? Out of the water!
Brody: It doesn't make sense that they pay a guy like you to watch sharks.
Hooper: It doesn't make sense for someone who's afraid of water to live on an island.
Brody: It's only an island when you look at it from the water.
Hooper: That makes a lot of sense.
Hooper watching some of the would-be shark-killers: "Ha ha, they're all gonna die."
Also when he describes the guys who are severely overloading their boat:
"You know those eight guys in the fantail launch out there? Well, none of them are gonna make it out of the harbor alive."