- It’s now the season for whale-hunting along the equator—the "Line"—and the crew are eager to obey Ahab’s orders to turn in that direction.
- Ahab spends long periods sitting on deck, using his quadrant (a navigational instrument) to take measurements of the ship’s position.
- He keeps comparing the exact location of the ship to Moby Dick’s likely position.
- Eventually, Ahab gets frustrated, because no matter how precisely he measures the ship’s location, he’ll never really know where Moby Dick is.
- He throws the quadrant down and tramples on it with his living foot and his bone leg.
- Starbuck and Stubb watch Ahab, worried about the eventual fate of the voyage.