The unknowability of the sea

The unknowability of the sea is a central concept in the novel: it drives Abel Jackson’s desire to understand marine life, exposes the limits of both memory and scientific explanation, and ultimately helps define a practice of care that does not depend on possessing every answer. The sea is encountered as a material world of depth, breath, and change, but also as a store of histories and perceptions that human beings can approach without fully retrieving. Abel’s lifelong questions remain unresolved; what changes is his understanding of how to live with that uncertainty.

A mystery measured in years

Abel’s curiosity begins with Blueback’s extraordinary age. During a school day spent thinking about the fish, he imagines all that Blueback might have witnessed around Robbers Head: creatures arriving and disappearing, boats and people passing, and the reef itself changing. A karri tree offers a contrast. Its growth rings can disclose its age and record droughts and good seasons, while human beings preserve experience through speech, stories, and remembrance. A fish’s years, by comparison, remain hidden. Abel cannot tell whether a fish remembers at all, or whether its death takes its accumulated history with it.

This difference turns age into more than a matter of counting years. Abel can imagine the duration of Blueback’s life but cannot enter the fish’s experience of it. The question of what a fish thinks becomes inseparable from a broader one: whether human categories of memory and knowledge can describe a nonhuman life. Abel does not dismiss that possibility as unknowable in principle; he longs to learn what Blueback knows. But the novel keeps the gap between that longing and access to the fish’s mind intact.

The question extends from fish to whales. When Right whales surface around Abel and Dora Jackson’s boat, Dora recalls that the Jackson family once hunted them from longboats after spotting pods from a lookout on the ridge. Abel wonders whether the whales remember. Dora cannot know, and hopes they do not. The encounter places human history and possible animal memory beside one another without resolving their relation: the people can recount the hunt, while the whales’ experience remains inaccessible. Their decision to stop fishing and watch gives the unanswered question a practical consequence. Attention replaces activity, at least for that moment.

The sea as a physical limit

The novel makes uncertainty bodily as well as intellectual. Abel’s early dives with Dora Jackson depend on limited lungfuls of air: he surfaces panting, then returns to the bottom, where they take only a couple of abalone from each clump and leave the rest to grow and breed. The underwater world is vivid and observable—rock, sediment, seaweed, coral, and reef fish—but a diver encounters it in temporary intervals bounded by breath. The sea can be closely observed without becoming a place a person can inhabit without limit.

That vertical rhythm complicates the idea that more looking must lead to complete knowledge. Abel and Dora work along the seabed, but their dives end when their air does; the creatures and processes continue beyond the duration of a human visit. The sea is not simply an object at a distance. It surrounds the observer, presses on the body, and sets conditions on what can be seen and how long it can be seen. The material limit of breath becomes an image of a wider epistemic limit.

Abel also wonders whether the sea’s creatures remember the people and events that have passed through it. His father, Abel’s father, died when Abel was two, after a Tiger shark attacked him during a pearling season in Roebuck Bay. The crew recovered his fins but never his body. In a dream years later, Blueback leads Abel through drowned people to his father, still a young man at thirty-two. Abel reaches toward him, but Blueback swims upward and keeps him out of reach. The dream gives form to Abel’s desire to recover what the sea has taken, while withholding that recovery: the father remains visible but inaccessible, and the dream does not turn the sea into a reliable archive.

The pursuit of explanation

Abel responds to uncertainty by imagining study as a way through it. After swimming with Blueback, he decides he will study fish until he knows what they think and become an expert. The ambition joins scientific inquiry to an intimate, almost impossible question: not only how fish behave, but what their lives mean from within. His later decision to attend university follows a related puzzle. When dead pilchards are reported along the coast and Dora says the ocean is sick, Abel wants to figure out what is happening.

At university, Abel studies through computer modelling, books, specimens in jars, photographs, films, and field trips. He dives in new places, but the sea he feels on his body remains familiar. These methods extend his reach and give him professional expertise; they do not grant access to what fish think. Between semesters, back at Longboat Bay, he recognizes that he is no closer to answering that original question. The contrast is not between worthless science and perfect intuition. Abel becomes a marine biologist and an invited expert, but the central mystery that first drew him to the subject survives his education.

His work also brings him into contact with environmental damage. Diving in the Greek islands, he sees an underwater desert created by dynamite fishing and pollution. Later, from far away, he watches reports of an oil tanker breaking apart off the coast of Longboat Bay. The slick burns and is dispersed by bad weather before oil reaches shore, but Abel understands how close the coast came to disaster. The sea’s complexity is therefore not a reason to stop investigating it: the stakes of human action are concrete even when the whole system cannot be understood or controlled.

Knowledge by staying

Abel’s eventual recognition of Dora Jackson’s knowledge revises, rather than simply abandons, his scientific ambition. In a conversation with Stella on the flight home, he reflects that he has travelled, studied, lectured, and become a prominent scientist, while Dora has remained at Longboat Bay, growing vegetables and eating fish. She has saved a place by staying there, watching and listening and feeling its changes. Abel understands her knowledge as grounded in sustained attachment to the bay, not in equipment or credentials alone.

That insight does not make Dora omniscient. The novel has shown her confronting unexplained ecological changes and speaking of a sea that is not right; it has also shown Abel wanting to know what Blueback might reveal about the water and about his parents. Instead, her knowledge arises from duration and attention. Her life among the seasons and inhabitants of Longboat Bay gives her a kind of understanding that cannot be detached from place and reduced to a single answer. Abel’s account of it is also a recognition of his own distance: he has gone away to study the sea, while the person he thinks understands it best has learned by remaining part of the bay.

The contrast is especially significant because Abel’s departure is not portrayed as a mistake. He leaves for school and work, becomes a marine biologist, and travels with Stella through oceans and seas around the world. He needs those experiences to pursue the questions that have occupied him since childhood. His return does not settle the difference between professional science and local knowledge; it allows him to see that neither kind of learning makes the sea wholly legible, and that knowledge can also consist in observing, listening, and responding to a particular place.

Unfinished knowledge and restraint

Even after returning to Longboat Bay, Abel and Stella continue to work as scientists, receive visitors, and watch, listen, and read. They never discover the sea’s secret. Abel imagines that Dora understood more, that his father did too, and that Mad Macka may have had some ideas; he accepts that his own time for understanding may come eventually. The possibility remains open, but the novel gives no final revelation that would turn the sea into a solved problem.

The oil tanker near-disaster sharpens the distinction between knowing everything and acting responsibly. No oil reaches the shore, yet the warning matters because the coast was vulnerable and the outcome depended on events beyond Abel’s control. Similarly, the bay’s recovery and flourishing under sanctuary protection demonstrate that human decisions can help create conditions for marine life without disclosing every secret of that life. Ecological care is not presented as the reward for total knowledge. It is a response made under conditions of partial understanding.

The final image carries the uncertainty into another generation. On Little Dora’s third birthday, she dives with two adults off Robbers Head; a huge blue creature emerges from a reef crack, and her eyes widen behind her mask. The scene does not explain what the creature knows or what the child will learn. It returns the reader to the encounter between human attention and a life that exceeds it. Abel’s lasting answer is not mastery, but restraint: he lets the sea be itself, continuing to learn without claiming to have exhausted what it can mean.