I never thought I’d crush on a guy named Martin, but Chief Martin Brody is just the kind of hero I love. He’s smart and loving and brave and flawed. He embodies responsibility, especially when everyone else in the town abandons theirs in the interest of greed and the need for the status quo. He overcomes his fear of the water to go after the shark because he feels no one else will do it.
His fear of water is a textbook case of an obstacle a hero must overcome.
But of course he can’t just look at it from the water, not when a shark is attacking his new home and the safety of the people he’s sworn to protect. He takes the responsibility to close the beaches, ordering handwritten signs over the protests of the mayor and council who refuse to see the dangers. When Mrs. Kintner approaches him and slaps his face, after she finds out he knew about the shark and did nothing, he takes the responsibility, though he did everything in his power to that point.
I think that’s why he chooses to go on the boat with Quint and Hooper, to make sure the shark problem is taken care of once and for all. It was odd to me that he’d choose to go, but in light of his dealings with Mrs. Kintner, I suppose it makes sense. The greater danger to those he’s responsible for is on the water, not back in Amity. It’s the heroic thing to do, see the quest through to the end. And Chief Brody is a hero.