In one scene, Valerie's outfit loses the pink bottom section.
In two scenes, Valerie's feet are the same color of her shoes.
Throughout the episode, Valerie's pink sleeves turn purple four times.
Valerie's purple shoes turn black in one scene.
When the group escape on the raft, Valerie's skin is white in one scene.
When the gang's going back to the Dixie Queen on the log, Velma is missing.
Although their shadows are seen, Shaggy and Scooby are missing from the title card. However, the flashlight projects onto Josie and the Pussycats as if they both were there.
When the ghosts fall overboard during the final confrontation, Alexander's voice comes out of Alexandra's mouth.
After Shaggy says, "I'll take the 'no ghosts,'" Alexandra's voice comes out of Alexander's mouth when he says, "Me three," and when he screams while running down and back up the gangplank.
There are numerous occasions when characters continue moving their mouths after their sentences are finished, particularly in the first scene.
The drama about Injun Joe's ghost would only make sense if the Tom Sawyer story is treated as having really happened. Yet the characters specifically acknowledged Mark Twain's fiction when they were coming to visit the riverboat.
Although Velma says that Injun Joe has a chain dragging from one wrist, in fact, his hands are manacled together.
After one of the ghost traps catches Captain Canaby, Fred tells Valerie to turn off the trap, but it shows Velma doing it instead.