Corrected entry: Since there's no light sources in the ship Antonia Graza, where does all that blue light come from in all the night scenes? Every window and even the inner rooms always have enough light to read a book.
Corrected entry: In the flashback, Francesca has just shot the crewman from the ship and he falls just in front of her. After the demon kills her, the crewman is nowhere to be seen. Neither of the characters move him, so where could he have gone?
Correction: You can see him, lying face down on the floor.
Corrected entry: The girl that survives was maybe about, what, 10ish? I would think she would have been tall enough that if all the adults got sliced just about in half, she'd probably have been decapitated.
Correction: If you watched, the captain ducked her down so she wouldn't get sliced. That's why he was sliced through his mouth.
Play the opening scene slowed down on YouTube and you can see the Captain simply hugging the little girl (Katie) as the wire makes its way towards his face. The wire started moving at waist height through most of the passengers, the only explanation of this error would be that the wire had some sort of spasm midway through its travel and found its way up high the second half of its trip, thus cutting the Captain from the mouth. If the wire would have remained at waist height, Katie would have definitely been killed, maybe not cleanly decapitated from the neck, but for sure anywhere around the head.
If you watch it again in slow motion, the Captain and the girl were in the middle of the dance floor so there's simply no way to explain it other than the fact the creators wanted the girl to survive while providing a shock factor (i.e. camera pans onto the Captain's head bisected horizontally). In the original script, there was no cable mass bisect scene but the girl had a fate different from the rest of the guests as well, so the girl surviving the initial massacre was always intended.
Corrected entry: When Epps and the crew first enter the bridge of the Antonia Graza, Munder tests the ship's compass and discovers that it does not work. However, after the crew patches the ship and fixes the rudder, the compass magically starts working again.
Correction: The compass is controlled by the evil ghost on the ghost ship, he allowed it to work only to help the crew navigate past the rocks. Can't collect souls if the ship sinks...
Corrected entry: In the scene where blood is pouring out of the bullet holes into the pool causing the pool to fill up with blood, the pool fills up very fast. This couldn't be possible because the blood pooring out of the bullet holes were in little streams, and it would have take a much longer time for the pool to fill up with blood.
Correction: It is a ghost ship. Many things happen on the ship that can't be explained.
Corrected entry: In the scene where Greer is going to hug the Italian singer after she has gotten naked he falls down the elevator shaft face first. Later on when the little girl leads Epps to his body we see him laying on the elevator face up with the cables through his back.
Correction: If you notice, Greer falls with his weight towards his head, headfirst, as he's expecting Francesca to return his embrace. Thusly, it's quite possible he flipped over on his way down. His body is in the correct position at the bottom of the shaft for this to be feasible and when Epps peers down the shaft near the beginning, we see it's quite deep.
Corrected entry: The puzzle device with letters and numbers that Katie uses to spell out "I'm so bored" in the beginning is near the entrance when the crew arrives but is later visible in her room. While it's possible the Ferryman is moving it around, it seems unlikely given that (when it's in the room) he doesn't make any use of it to scare Epps.
Correction: Like you said, it's possible the Ferryman moved it around. It's a character decision that he didn't use it to scare Epps.
Corrected entry: Toward the end of the movie when Dodge shoots Jack, you see the camera move over the body. As this happens you can see a wheel track from the camera in the water on the floor. (01:18:30)
Correction: Actually, the entire floor's like that but it's not from the camera because this is just the style of the floor, with raised circles in it.
Corrected entry: When Julianna Margulies and her crew weld a metal plate on the inside of an oil rig to stop it from sinking, would the water not be rushing in on them? Wouldn't it be easier to weld from the outside?
Correction: If they had welded the plate from the outside, they would have been left behind by the Arctic Warrior.
Corrected entry: In the beginning when everyone was cut in half so was the cabaret singer. Later on in the film there is a flashback and she is killed by the soul collecter with a hook while getting the gold.
Correction: The singer was not cut in half. She was inside the ship in the dining area singing while the people who were cut in half were out on the deck. She was killed in the manner they showed in the flashback.
Corrected entry: When the crew of the Arctic Warrior first encounter the Antonia Graza, they have to be hoisted onto the ship, via crane. When the Arctic Warrior explodes and sinks, the crane sinks with it. How did the crew get back onto the Antonia Graza?
Correction: There is a hoist on the ghost ship that was used to load the repair supplies earlier in the movie. Could they not use that as the Captain was still on board?
Correction: Moonlight.