Of all the symbols in the book, water—and by extension, the sea—is the most prominent and powerful. Its forces shape the lives of the main characters for better and for worse. Water is so important that the word for it in Vietnamese (nước) means “homeland” or “nation” as well, as the author mentions at the beginning of the book. The book’s entire scope is shaped by three water-related events: the death of the Girl’s brother by drowning in the sea; the flight of the Girl and Ba by boat in the South China Sea; and the family’s move across the ocean to America, in which a body of water separates them from Vietnam.

Because of the family's traumatic incidents, water—and the sea—take on dark, negative elements, such as when Ba goes fishing and describes the water at his feet as the only dark spot in the city, or when Ma describes the water in her dead son as a heavy burden: “It was the water. The water was heavy” (139). Ma feels guilt over not protecting her son. Ma projects these feelings into anger at water, such as when she violently pushes a bucket of water back into the family well after seeing her reflection in it.