How we cite our quotes: (Paragraph)
Quote #4
We are surely doomed to hover continually upon the brink of Eternity, without taking a final plunge into the abyss. (20)
Maybe he's just being melodramatic here, but you could read this as telling us that narrator has died, and is somehow stuck somewhere between this life and the next, unable to move on.
Quote #5
Concealment is utter folly on my part, for the people will not see. (14)
If the crew can't see the narrator, it may be because they're the ghosts of the dead… or he is. Now there's a chilling thought.
Quote #6
The crew glide to and fro like the ghosts of buried centuries. (22)
Notice the use of the word "like" here. It suggests that the crew are ghosts without actually coming right out and saying it. But that's close enough, right? For all their creepy, aloof behavior, they might as well be specters.