• Historically: The Middle Passage was the middle leg of the triangular slave trade: enslaved Africans were forcibly transported across the Atlantic to the Americas and Caribbean. On the Zong, disease, overcrowding, starvation, and brutal treatment lead Captain Cunningham to order enslaved people thrown overboard.
• For Mintah: The voyage represents a state of being “between” two lives. She has been violently separated from Africa but has not yet reached her destination. The sea therefore becomes a kind of limbo between her past and an uncertain future.
• As a symbol: D’Aguiar presents the sea as a place where the identities and histories of enslaved people are threatened with being erased. At the same time, it becomes a place where their “ghosts” and memories survive. Scholars describe the sea in the novel as a suspended or endless Middle Passage.
• Memory and history: The novel is also about recovering the stories of people who were treated as property rather than human beings. Mintah's survival and attempt to record what happened challenge the official historical record.

• The Middle Passage is essentially the central setting and metaphor of the novel. D’Aguiar uses it to show the physical horror of slavery, but also the psychological effects of being forcibly removed from one's homeland.
• The Middle Passage is not simply a sea journey; it is a liminal space between life and death, Africa and the New World, and historical memory and forgetting.
• This connects directly to the novel's title: the drowned enslaved people become “ghosts”, and Mintah's remembering and retelling of their lives becomes a way of keeping them from disappearing completely from history.

So there is a paradox: the sea contains memory precisely because it contains the dead, but it also threatens to erase memory because the dead cannot speak.

This is important because the sea becomes a kind of archive without a written record. The people thrown overboard leave no graves, names, or physical remains that can easily be recovered. Their memories seem to disappear into the ocean.

Later, the novel describes the sea as a “road of bones” (pp. 37 and 213), turning the ocean into a metaphorical memorial to those who died during the Middle Passage.

For Mintah, land is associated with recoverable memory—her childhood, family, community, and African home—whereas the sea represents an “in-between” existence in which normal time and memory are suspended. One scholarly reading argues that Mintah's memory effectively becomes the land itself, while the sea represents the traumatic space separating her from that memory.

This gives you a strong contrast:
land = memory, identity, ancestry
sea = displacement, trauma, forgetting.

That means the sea traps the enslaved people outside ordinary historical time. They cannot return to the past, but they have no meaningful future either. Their memories of Africa therefore become extremely important: remembering is one of the only ways they can resist the sea's erasure of their identities.

This is significant because the sea that Cunningham imagines as a place where evidence disappears becomes, ironically, a place where memory refuses to disappear. Scholars describe this as the point where the novel connects personal memory with historical memory.