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)
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.
Continuity mistake: When Rennie and Sean are on the ladder in the sewer Rennie's position changes between shots. (01:29:50)
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.
Continuity mistake: When we see Jason lying on the bottom of the lake, we also see some chains lying around. At first we see the upper chain lying out on the edge of a plank. But when Jason gets electricity through him we see the chain has moved in to the middle of the plank. (00:06:15)
Continuity mistake: In the film Sean and Rennie are on board the Lazarus. Sean puts both of his hands into his jacket pocket to get Rennie's gift. He never hands it to her, but In the next shot she has it in her hands. (00:16:55)
Chosen answer: To the best of my knowledge, this is just a bit of a continuity mistake. While previous films have not indicated Crystal Lake is connected to the ocean, this film portrays it as being connected. You just kinda gotta go with it for the movie to work.
TedStixon