Chapter V recapitulates Augustus's efforts to make contact with Pym after the mutineers take the ship. There may be something there in terms of comparative narration, but that's not really what I'm after. Nothing struck me right away.
I was beginning to wonder about Chapter VI. Odd things going on: a diversionary lecture about proper cargo stowage in a ship's hold; the story about the lone survivor of a shipwreck whose cargo of corn shifted and brought the craft down; the details about the open spaces in the Grampus's hold; Tiger's recovery. But now it makes its own sense, because Poe/Pym has turned to journal entries to continue the narrative. Chapter VI is its own stowage, one of narrative rather than of material, and its attention to careful packing tells the reader that one's own narrative should be packed with equal care.