Melville retreats from the notion that Ahab’s quest for Moby Dick is pure insanity in this chapter

Melville retreats from the notion that Ahab’s quest for Moby Dick is pure insanity in this chapter, in which he reinforces Ahab’s seafaring knowledge and justifies the seemingly random quest for the whale by demonstrating that Ahab can make reasonable calculations concerning Moby Dick’s location. Yet this also reinforces the grand stature of the quest against Moby Dick by showing that Ahab has long planned the Pequod voyage to best facilitate a confrontation with the white whale. Melville also once again reminds the reader of the great psychological weight that Moby Dick places upon Ahab, afflicting him even in his dreams.
This chapter continues to develop the significant conflicts of the novel, primarily the internal struggle that Ahab faces between his prudent and rational nature and his obsessive impulses against Moby Dick. As a ship captain, Ahab cannot abandon his duties on the voyage, yet this is the only hindrance he finds in his search for Moby Dick. Additionally, Melville continues to construct a conflict between Starbuck and Ahab by showing that Ahab knows that it will be Starbuck who will oppose his quest. The effect of this is to construct Ahab as an even more formidable antagonist, for despite his seeming insanity he remains knowledgeable of the motivations and attitudes of those around him.