Jaws

Jaws is to swimming what later film Friday the 13th is to camping. Hearing the first two notes of Jaws' theme starts a frenzy as it is synonymous with impending doom. Accompanying John William's score is the shark's perspective as it seeks out its prey making the scene much more intense.

Fear of the shark always lingers with low angled camera shots of feet scurrying across the shore.

Spielberg executes fear well without being overtly gory. He builds suspense by only giving hints as to how massive the shark is. The big pay off doesn't come until the end of the film, but not before a tease of its head popping out the water shocking the main character and the viewer.

The shot below foreshadows the boats demise in a subtle way.
As Hooper and Chief Brody swam back to shore I was left thinking Jaws isn't the only shark in the water. Who is to say they get there safely?

Trivia

• The color red is never used in any clothes or any backgrounds as Spielberg wanted it to be only seen as blood.
• After the shark was built, it was never tested in the water, and when it was put in the water at Martha's Vineyard, it sank straight to the ocean floor. It took a team of divers to retrieve it.
• To create the sound of a drowning woman during post-production, Susan Backlinie was positioned, head upturned, in front of a microphone, while water from above was poured down into her throat
• SPOILER: Quint's name comes from the Latin word for "fifth". Quint is the fifth person killed by the shark (after Chrissie Watkins, Alex Kintner, disembodied head in boat, and Michael's sailing teacher).
  
  

Sources:
IMDB
Horror Stew