David chooses not to give into his grief immediately, in part because he wants to conceal the deaths of Ham and Steerforth from little Em'ly and Mr. Peggotty. He does, however, tell Mr. Micawber what has happened so that he can help David by intercepting newspapers or other reports of the accident.
If there were any remaining doubt about how much David has grown over the novel, his self-possession in the wake of Ham's and Steerforth's deaths lays it to rest. In fact, David at this point is choosing not only how he will respond to the deaths, but also—in withholding information from them—how Emily and Mr. Peggotty will. This choice might seem questionable, but it's in keeping with David's growing agency, as well as his career as a writer; David is no making decisions about how and whether to "depict" events in real time.
David entrusts Mr. Micawber with this task while he and his family are staying in a public-house, just before setting sail. Traddles (who also knows about the accident) comes with him, and Agnes, Miss Betsey, and Peggotty are already there helping the Micawbers pack. Mr. Micawber is in a very good mood, and has dressed himself in a "nautical" fashion. Miss Betsey asks him when the ship is leaving, and is surprised to learn that they need to be on board the next morning, and that the ship will set sail the day after that. Mr. Micawber then asks permission to make punch one final time. He prepares it with a pocket-knife and serves it in "a series of villainous little tin pots." As he drinks his punch, he talks delightedly about renouncing "the luxuries of the old country."
Far from being disheartened by the challenges of life in Australia, Mr. Micawber takes great pleasure in imagining the coming hardships. This speaks to Micawber's theatrical personality, but it's also a reminder of why Micawber will ultimately succeed in Australia: there isn't a rigid class hierarchy in place, so all that counts, according to Dickens, is the ability to work hard.
A boy arrives saying that someone wishes to see Mr. Micawber, and Mrs. Micawber says she expects it is a member of her family. Mr. Micawber threatens to leave them waiting as payback for their treatment of him, but Mrs. Micawber urges him not to snub a genuine attempt at reconciliation, if only for her sake. Mr. Micawber accordingly agrees and goes downstairs, only for the boy to return with a note explaining that Mr. Micawber has been arrested, and is in a "final paroxysm of despair." David goes downstairs and pays off the debt, and Mr. Micawber embraces him and notes the amount in his pocketbook. This reminds him to give a sheet detailing all his debts, with interest, to Traddles. Meanwhile, Mrs. Micawber still thinks her family will show up before the ship sails.
Mr. Micawber's willingness to forgive and forget his wife's family contrasts sharply with Uriah's vengeful and repeated attempts to have Micawber arrested for betraying him.
Mrs. Micawber promises Miss Betsey and David she will write from aboard ship, if she is able to. Mr. Micawber doesn't doubt his wife will have opportunities to write, because "the ocean, in these times, is a perfect fleet of ships," and "the distance is quite imaginary." David is struck by the fact that while Mr. Micawber talked about moving to Canterbury as if he were making an enormous journey, he seems to view going to Australia as a "little trip across the channel." Meanwhile, Mr. Micawber talks excitedly about what they will see and do on the upcoming voyage.
Mr. Micawber is as optimistic about going to Australia as he has been about all his previous ventures. In this case, however, the radically different kind of society he is joining will finally allow him to succeed; in fact, only someone with Micawber's optimism would make the journey in the first place.
Mrs. Micawber says she hopes that her descendants might one day return to England, but Mr. Micawber says he does not feel especially indebted to England, which "has never done much for [him]." The couple argues over this, with Mrs. Micawber urging her husband to see emigration as a way of strengthening "the connexion between [himself] and Albion." She then appeals to David, saying she wants her husband to appreciate his "position": Mr. Micawber should demand that Australia appreciate his talents and offer him "honours," "riches," and jobs. She therefore wants him to assert himself and "be the Caesar of his own fortunes." This, she says, will naturally cause him to become famous and respected in England as well. Mr. Micawber, moved by his wife's faith, says he wouldn't "grudge [his] native country" a share in his future wealth.
Although it's played for comedy, the argument between Mr. and Mrs. Micawber crystallizes the question of how well English society lives up to its claims of being a meritocracy. In urging her husband to be the "Caesar of his own fortunes," Mrs. Micawber is adopting an exaggerated version of the language surrounding self-sufficiency and personal agency. Furthermore, she believes that exhibiting this kind of independence automatically entitles a person to wealth and success. This isn't an unreasonable expectation, given that Victorian society did maintain that hard work and self-discipline would be rewarded.
Miss Betsey drinks to Mr. Micawber's words, and Mr. Peggotty and the Micawbers then toast the whole group. David is struck by Mr. Peggotty's good humor, and expects that he will do well in Australia. Agnes and Miss Betsey then say their goodbyes, causing both Mrs. Micawber and her children to burst into tears.
David's intuition about Micawber's future success proves to be correct. Although Mr. Micawber's optimism has gotten him into trouble in the past, it's the kind of trait required to relocate somewhere far away and—in the English imagination—unsettled.
David returns to the public-house the next morning and finds that the Micawbers have already left. The following afternoon, however, he and Peggotty go to visit the emigrants on board the ship. Mr. Peggotty is on deck, and explains that Mr. Micawber had yet again been arrested, and that he paid off the debt for him. David repays Mr. Peggotty and then accompanies him below deck, where they meet Micawber himself. David, who had been slightly worried that Mr. Peggotty might have heard something about Ham, is reassured by the fact that he has been spending almost all his time with Mr. Micawber.
David continues to take charge of circumstances in this passage, overseeing the responsibilities he's tasked both Mr. Micawber and Mr. Peggotty with—keeping Mr. Peggotty in the dark about Ham's death and preventing Micawber from being arrested.
David takes in his surroundings, watching as people say goodbye to loved ones and strike up new relationships with fellow passengers. The ship is very crowded, and it seems to David that "every age ad occupation [is] crammed into the narrow compass of the 'tween decks."
Dickens depicts the ship going to Australia as a cross-section of English society, implying that a colony like Australia reproduces in miniature the country that established it; David even remarks that some of the passengers, like the ploughmen with dirt all over their shoes, are physically carrying part of England with them. This depiction of colonization characterizes it as a natural extension of Victorian values of determination and personal agency, rather than as a measure of British society's inability to accommodate its entire population (or, of course, as an intrusion into already inhabited areas).
While he is looking around, David sees someone who looks like little Em'ly sitting with one of the Micawbers' children. He also sees a figure who resembles Agnes embracing and walking away from this woman. He then loses track of both figures, however, as all visitors are ordered to leave the ship.
The figure David sees here likely is little Em'ly, since Mr. Peggotty will later tell him that Emily spends much of her time helping others with their children. Although this represents a kind of reintegration into family life following her affair with Steerforth, it also draws attention to the fact that the novel doesn't allow Emily to have a family of her own; she's tainted for the rest of her life.
Mr. Peggotty asks David whether he has any final words for him, and David mentions Martha. At this, Mr. Peggotty gestures to a young woman who is helping Mrs. Gummidge with the luggage, and David sees that it is Martha. Martha, overwhelmed, begins crying, and David shakes Mr. Peggotty's hand and blesses him for taking Martha with him.
Besides serving as another reminder of Mr. Peggotty's generosity, Martha's presence provides an interesting contrast to little Em'ly. Unlike Emily, Martha actually does go on to marry in Australia; in fact her husband even knows about her past and disregards it. This suggests that Emily's decision not to marry is perhaps a form of personal penance. On a narrative level, the difference in the two women's fates may also reflect the fact that Emily was at one point a love interest of the novel's hero, and must therefore be "punished" for her transgressions in a way that Martha is not.
David relays Ham's parting message to Mr. Peggotty, and Mr. Peggotty—still ignorant of Ham's death—gives David a message to relay to Ham. David then says his final goodbye to Mr. Peggotty, and leads Peggotty, who is crying, back up to the deck. There, they say goodbye to Mrs. Micawber, who insists one final time that she will never leave Mr. Micawber. Peggotty and David then disembark, and watch from a distance as the ship gets underway and everyone on board cheers. At that moment, David catches a glimpse of little Em'ly, "surrounded by the rosy light," leaning on her uncle and waving goodbye. By the time the ship is out of sight, however, night has fallen, and everything seems dark to David.
David's description of Emily in this passage is heavily romanticized and, like his avoidance of her since her return, seems in part like a way for David to avoid confronting any lingering feelings he has for her. David's interest in helping see the emigrants off is also a form of avoidance—in this case, a distraction from his grief over Dora and Steerforth. The moment the ship leaves, David loses this purpose, and falls into a state of deep depression.