In the chapter called "The Whiteness of the Whale," Ishmael discusses two meanings assigned to whiteness. It is both a symbol of terror and a symbol of beauty.
In speaking of the whiteness of a whale like Moby Dick or the whiteness of a polar bear or any other fearsome creature, Ishmael notes that encountering whiteness can "heighten ... terror to the furthest bounds."
On the other hand, as Ishmael notes, white is associated with beauty:
In many natural objects, whiteness refiningly enhances beauty, as if imparting some special virtue of its own, as in marbles, japonicas, and pearls.
These two competing meanings of whiteness point to the elusive and ultimately unstable qualities of human perception. What we see and experience with our bodies is ambiguous, leading to the question of how do we truly know what is good and what is evil? How, more specifically, can Ahab be so unquestioningly, relentlessly sure that Moby Dick is evil incarnate?
"There she blows," on a literal level, refers to the water that spouts from a whale's hole, allowing it to breathe and allowing the sailors to spot it so they can kill it. But as the novel notes, the phrase also symbolizes the endless repetition of life's toil, which is, paradoxically, the fabric of life itself. The sailors
[hear] the cry of "There she blows!" and away they fly to fight another whale, and go through the whole weary thing again. Oh! my friends, but this is man-killing! Yet this is life.
A typhoon hits the Pequod violently and blows it off course, but more tellingly, it damages the lodestones that control the compasses. The men can see by the sun that the ship is heading west, but the compasses are pointing east. Ahab, with unflappable confidence, fixes the unsettling problem. As the chapter ends, Ishmael describes Ahab as follows, foreshadowing the pride that will doom them all:
In his fiery eyes of scorn and triumph, you then saw Ahab in all his fatal pride.