Continuity mistake: When the Seagrass is attacked, the two girls are thrown through the cabin's rear windows, landing on the outside deck. When the boat's owner finds it, a camera circles the Seagrass from a distance and the rear windows are intact. When he and Elizabeth board the boat, the windows are again broken. (00:26:40 - 00:42:15)
Continuity mistake: As Stevie's car settles to the ocean bottom, an exterior shot looking at the front/driver-side shows her door mirror is missing. But when she wakes up and looks around, the mirror is on the door. (01:16:20)
Continuity mistake: As Elizabeth is being driven home in Nick's pick up truck, all the glass suddenly shatters. It is shortly before 10pm (clock at her mom's house). But despite the fact that Nick and Elizabeth are busy all the next day, the truck is over 30 years old, and the story takes place in a small, island community, all the truck's glass is back when it's seen the next afternoon - both the front & rear windshields, door glass and vent-windows, and it's all just as dirty as it was before the breakage. (00:22:40 - 01:10:30)
Continuity mistake: When Nick crashes his truck into a boat and trailer, Elizabeth is shown being tossed around inside the truck in slow motion as the truck settles to a stop. But in the scene showing the aftermath of the crash, she's regaining consciousness on the ground a good fifty feet or so to the right of the truck. (01:22:00 - 01:23:20)
Continuity mistake: When Nick is driving Elizabeth home, he mentions buying her a ring. The steering wheel is the standard hard plastic type found on trucks of it's era. When the glass shatters and the truck comes to a halt, the wheel is suddenly padded with a black, aftermarket wrap. (00:22:10 - 00:22:45)
Continuity mistake: When Stevie's car falls in the water, the damage to the hood (as the car meets the water in the distant, slow-motion shot) is very different from two shots later (just before the front of the car sinks out of view). (01:15:55)
Continuity mistake: When the two men and two women are on the Seagrass, the women are in the cabin when the Fog first strikes. The windows fog up and the blonde woman draws a scale on the window. The drawing differs between her drawing it and the close up. Notice the lines on her drawing extend beyond the base lines of the scale the close up lines do not.
Continuity mistake: Towards the end of the movie the DJ is driven off a cliff. She escapes, but when she finds her son she is all dry.
Continuity mistake: Stevie's radio station is shown located in a lighthouse, yet the night shot early in the film shows an entirely different lighthouse than is seen in daylight mid-way through the film. The later version's top, red portion isn't nearly as tall, and it has at least a third of its glass replaced with solid panels, while the earlier one is taller and all glass. (00:13:35 - 00:47:35)
Continuity mistake: In the scene where the paramedics are removing the bodies from the Seagrass it shows them putting a sheet over the one girl and guy that were killed and moving them into the vehicle, which would have left one other body. but in the next shot from above there are two bodies laying on the dock with sheets over them.
