I love how cautious Brody is in this scene, he speculates that there’s a shark on the loose and is trying to prove something as a police. Knowing that his kid is swimming right now makes it pretty engaging and suspenseful.
The way people keep coming up to him and blocking his view and he just ignores them is really just to show how focused and caution he is during the scene. You still hear the audio of people talking but the audience is engaged where Brody is looking instead, making what there talking about is bland probably on propose so you stay focused more on what is happening in the water.
When the shark attacks you can see ford is stressed and feels like he just failed.
POV Shot of the shark makes it more scary with the people having no idea the shark is swimming right under them, Nice addition.