Ensign Carmody takes Willie and Harding on a tour of the ship. For three hours, the ensigns explore every nook and cranny of the ship. Their final task is to climb the mast to the crow's nest. Once inside the nest, Harding says that he has to throw up. Willie offers his hat as a receptacle for the vomit. After dinner, there is some discussion about the terrible conditions in the clip shack, but the other officers do not want extra bunks in their quarters. Willie says that the bad conditions don't matter, which earns him an approving glance from Captain De Vriess. Willie and Harding begin their officer's qualification courses under Lieutenant Adams, an aristocratic regular officer. Their first assignment is create port and starboard diagrams of the ship by recalling what they saw on the tour. Desperate for sleep, Harding suggests that in the morning they copy a diagram from the ship's operating manuals. They head off to the clip shack, but find it filled with thick black smoke. After tossing and turning for a few hours, Willie leaves the shack and goes to sleep on a couch in the officer's wardroom.
Willie is woken up by a call to the four-to-eight watch. Willie attempts to run the watch as he was taught in officer's school, but the crew is not used to his stringency. They slack off, and Willie has to repeatedly scold an enlisted man named McKenzie for falling asleep on duty. Willie is shocked later by the crew's slow response the call of reveille. At breakfast, Keefer asks for help with decoding. Willie begins to help, but soon falls asleep. The captain comes and says that Willie should have had enough sleep from his Pearl Harbor duty to last a month.
Later that day, Willie is awakened to hear that Roland Keefer and two beautiful nurses came to visit him. De Vriess makes Willie finish his sketches of the ship before letting him leave. Willie angrily does the drawings while the captain entertains the girls next door. Willie finally leaves with his friends. He is in a terrible mood and drinks more than he ever has before. Early the next morning, a messenger wakes him with word of an urgent action-item that needs decoding. Willie is delighted to see that the message indicates that Captain De Vriess is to replaced by Lieutenant Commander Philip F. Queeg.
After four days of repairs, the Caine gets orders to head to sea. The mission is a simple minesweeping exercise, and the officers gripe about the insignificance of their role in the war. Keefer has been particularly disillusioned by his time on the Caine, and dreams of duty on aircraft carriers. He tells Willie that monkeys could do ninety-nine percent of Navy work, and the other one percent could be done by administrators in the States. Keefer says he is writing a novel about the war, which is set on an aircraft carrier. Willie later learns that Keefer's novel distracts him from his normal duties, which annoys the rest of the crew.
Captain De Vriess is forced to make a tricky maneuver to get out of the harbor, but he succeeds easily, and the Caine proceeds to its minesweeping exercise. They arrive at their rendezvous with the minesweeper DMS Moulton. Willie remembers that Keggs is stationed aboard the Moulton, and decides to flash him a greeting in Morse code. Willie is interrupted and harshly reprimanded by De Vriess for breaking his communication authority. De Vriess also reprimands the sailor of the watch for letting Willie to send the message. Willie stalks off, fuming that the captain picks on him and lets the rest of the crew misbehave.
At four o'clock, the minesweeping begins amid whirling bodies and profanity from the crew of the Caine. The gear is deployed in forty-five minutes, well below the Navy's recommended allowance of one hour. Still, Captain De Vriess criticizes the crew for falling short of his personal expectations for a thirty- minute launch. Willie first attributes the speed and precision of their launch to luck. His belief becomes awe as the Caine performs a complex series of minesweeping exercises. A radioman tells Willie that there is an urgent action item to be decoded. Willie shoves the communication in his pocket, and watches Maryk, who is performing a tricky maneuver. A wave sweeps over Willie and the communication, completely forgotten, dissolves to mush in the seawater.