Red Alert

The ferry scene opens with a long shot of a stretch of water, a strip of beach in the background and beyond that green vegetation. Two marker buoys with red flags are positioned close together on the right of the screen with a third on the far left. On the right side of the frame a group of six swimmers can be seen splashing vigorously in pursuit of a man in a red tracksuit rowing a red boat. It's quite possible that this is the same red boat that will be capsized by the shark in the pond and if it is then the estuary victim was Amity's local scoutmaster.

 

Red has long been visual shorthand for danger. Hitchcock drenched the screen in it to convey hysteria in Marnie and even inserted a few crimson frames to the otherwise monochrome Spellbound for maximum dramatic effect. Brian de Palma's Blow Out, M.Night Shayamalan's The Sixth Sense and The Village, and Douglas Sirk's Written on the Wind are a few of the titles that immediately come to mind when thinking of the use of red as a visual signifier.

Spielberg made a decision early on in pre-production to avoid the colour as much as possible so that when the ocean turned red in the shark attack scenes the impact would be all the greater. In transferring Jaws from the page to the screen the most significant adjustment in the colour scheme was to make the Orca's barrels bright yellow - in Benchley's original novel they are red. Yellow is the preferred colour for safety and rescue equipment at sea because of its high visibility, and for the same reason is commonly used as a background to warning signs. The movie exploits this safety/threat binary through its use of the colour and conditions the viewer to respond to it with a growing feeling of unease.