Continuity mistake: When Rennie goes to the bathroom after the scene where she gets thrown overboard, her hair is still wet but her clothes are completely dry. (00:32:05)
Revealing mistake: When Tamara is thrown into the mirror, in the reflection you can tell that it is a stunt-woman. (00:36:50)
Continuity mistake: Not long into the movie, Reni is looking for her dog. Next time we see the dog, it is on her lap in the life boat. Between these two scenes they never show her finding the dog: it just appeared out of nowhere.
Revealing mistake: When Jason breaks his hand through the door it's really strange how his hand makes a perfect square on the broken door. Telling that the door was already broken and then repaired loosely for the stunt.
Continuity mistake: When Jason, as a kid, comes out of the mirror and grabs Rennie by her throat, Jason's grip on her throat differ between the shots. (00:32:00)
Continuity mistake: After Jim is stabbed, he smears blood over a window. Later when we see the boat drifting towards the harbour, we see the window and the smears of blood are now much different. (00:09:40 - 00:12:30)
Continuity mistake: The arrow that Jason shoots at Suzi which hits the wall beside her changes angle when he rips it out of the wall. (00:09:20)
Continuity mistake: In the film Jason kills the guy in the sauna with a hot coal into his stomach, and there's no blood. When Jason leaves you can see the guys chest and now it's covered with blood. (00:28:45)
Revealing mistake: When we see a wide shot of the ship in the storm we can see the ship slide through the waves untouched by them. It's obvious the scene is a composite. (00:35:45)
Other mistake: When Jason is resurrected in the lake, the water is quite well lit, even though it's night and there aren't any real light sources to light the lake up. (00:06:00)
Continuity mistake: Somehow Jason acquires a pair of gloves he didn't have in Part 7: The New Blood.
Continuity mistake: When Jason is holding Eva in the air, he lifts her up higher towards the ceiling, but in the shots of her feet, they stay in the same position.
Continuity mistake: Crystal Lake goes from a lake surrounded by land in previous installments to suddenly having the space for a small yacht and a channel that feeds right to the open ocean.
Factual error: Jason put Shawn's dad up against the ships wheel. Dead bodies can't stand up.
Visible crew/equipment: When Sean and Rennie come up the stairs just before finding Sean's dead father, as the camera moves backwards, you can see the camera's shadow on the wall to the right. (00:39:40)
Continuity mistake: When Rennie and Sean are on the ladder in the sewer Rennie's position changes between shots. (01:29:50)
Revealing mistake: During the part where J.J. goes down to the boiler room to play her guitar, Jason sneaks up behind her. She screams and runs down more stairs, and then right before Jason kills her, as he lifts the guitar to hit her, in the lower right hand of the screen you can see the blood coming out of the guitar before it hits her. (00:21:25)
Other mistake: Rennie shouldn't have been able to get on the boat at all. Being high school students, they would need a permission slip signed by their legal guardian to board the ship, just like any field trip. And, it's obvious that Charles would not sign one allowing Rennie to board. He definitely voiced his objections to the female teacher. Rennie can't make that decision on her own as she did.
Suggested correction: It was a graduation field trip. They were no longer students. Therefore she didn't need permission.
Continuity mistake: The previous movie saw Jason looking dark greyish brown, here he's a slimy light grey and has gained a pair of black rubber looking gloves.
Continuity mistake: Rennie's visions of Jason as a boy change their appearance constantly throughout the film. At some points he is bald and deformed, much like how he was in the original film. At other times he appears as a normal, non-deformed boy with a full head of brown hair. At some moments he even appears as a mix of both (with a deformed face, but a full head of hair). This inconsistency is never explained or even acknowledged.
