LitCharts assigns a color and icon to each theme in Moby-Dick, which you can use to track the themes throughout the work.
Limits of Knowledge
Fate and Free Will
Nature and Man
Race, Fellowship, and Enslavement
Madness
Religion
Summary
Analysis
The Pequod passes the Bashee isles and heads into the Pacific Ocean, which Ishmael remarks upon for its calm and “serenity.” Ishmael notes that Ahab stands looking out at the Pacific, but does not seem to notice its calmness—instead, Ahab believes that the White Whale is to be found in that ocean, and he calls out to the crew that MobyDick “spouts thick blood,” and lies ahead of them.
What Ahab sees is determined not by the external world but by his internal world. He looks at a calm ocean, but sees only the tempest within. In the previous chapter Queequeg wrote his "book" on his coffin. Ahab, meanwhile, is also writing a book, which holds Moby Dick and him at its center, with everyone else a minor character.