Michael Brody: Dad died of a heart attack!
Ellen Brody: No. He died from fear. Fear of that shark.
Jake: C'mon, you big overgrown goldfish, come to Jake!
Michael Brody: I've always wanted to make love to an angry welder. I've dreamed of nothing else since I was a small boy.
Hoagie Newcombe: I have an irresistible urge to kiss you, Ellen Brody.
Ellen Brody: Why?
Hoagie Newcombe: Because... It would not occur to you why.
Answer: We never see Jake "eaten", he is merely shown being dragged underwater by the shark. Off screen, the shark simply let go of Jake and didn't kill him. In a movie full of factual errors and plot holes, this bit is actually somewhat realistic. Sharks typically do not eat humans, but will maul people on occasion and let go, presumably because they don't like the taste. How Jake survives underwater for minutes on end is not addressed. Originally, Jake was meant to be killed by the shark but for whatever reason, it was decided that Jake should survive and make a surprise appearance after the shark has been killed.
BaconIsMyBFF