James Franciscus' trouser keeps changing from light blue to dark red in the same scene.
In the 37th minute during the evacuation of the regatta participants, the sky keeps changing in between shots.
At minute 22:50 character Peter Benton states the record length for a great white shark is 28 feet. All of the science literature however suggests nothing longer than 20 feet has ever been documented.
In the 27th minute after the woman runs into the ocean and is knee-deep, a man 5-7 feet behind her dives in, meaning he would ended up in mud. In the next minute one see people diving into the ocean while other stand up, at knee depth.
In the 15th minute Peter speaking to Gloria an saying "Sorry kiddo, we didn't want you drifting out to sea" makes no sense because they are already out to sea.
36th minute: 'buoy' is pronounced 'boo'-ee,' not 'boy.'
When the shark pulls the WellsCo chopper down under the water, it changes from a Bell 206 JetRanger to a scale model of what appears to be a Bell 212.
Obvious dummy in the powerboat that is lifted into the air by the shark during the regatta.
In the 22nd minute Mayor Wells places a cigarette to his mouth three times but does not light it.
When the shark eats the bait from the chopper, stage light's can be seen reflected.