Secrets of the Sea, by Nicholas Shakespeare

Merridy, heroine of Nicholas Shakespeare's The Secrets of the Sea, says during a youthful discussion of the origins of life: "The sea. I could believe in that." Surviving in a world of bereavement, uncertain relationships and financial insecurity, Merridy does indeed put her faith in the sea. Fickle as the South Tasman Sea is at the best of times, it proves to be Merridy's only certainty. She learns to read its moods, and makes a living from the chancy oysters who insist on opening and closing their fragile shells at just the wrong moments. Merridy teaches herself to navigate so well that her homemade oyster boat becomes the most reliable lifeboat on her stretch of the coast.

As she engages with the sea, Merridy learns to love, suffer, improvise and take risks. For a while, solutions are deceptively simple, then hidden complexities surface, and create a climactic storm, which is predictably reflected in a turmoil of sea and weather. The question is how, and whether, Merridy and those close to her will survive.

Alex, Merridy's husband, only turns to the sea reluctantly, as he wrests a living from his rundown, marginal farm at the sea's edge. He works stolidly with his back to the sea, until it comes to him in the great storm that uproots all his trusted landmarks. Alex courageously saves a boy from a sinking brigantine, but it's an ominous rescue. Kish's arrival initiates the gradual exposure of repressed feelings and unacknowledged tensions. Both Merridy and Alex suffered violent bereavement as children.

Missing children reflect lost childhoods. Merridy and Alex's lives are barren until they plunge into their emotional depths and recover the childhood selves they each have drowned in forgetfulness. The denouement shows that the past that lives in memory is unreliable and deceptive. "Memory is a sieve," Merridy repeats again and again.

Reared on Edward Lear by her eccentric father, all Merrdiy's subsequent seafaring has been of the Jumblie variety: courageous but misguided – perhaps even silly.

Meanwhile, Alex, who lost both family and sea on one catastrophic day when he was 11, has only engaged with ships when they were painstakingly inserted into bottles, a craft taught him by his father. As for Kish, like the Flying Dutchman whom he pretends to be, he seems doomed to enact archetypal roles in other people's lives as he wanders on forever. His uncertain status makes him never seem quite real; it's hard for the reader to mind very much what happens to him.

The Secrets of the Sea is also a picture of a community: "a town on the sea without sea life". Wellington Point is a decaying seaside town at the south end of Tasmania. The author of the Newsletter turns out to be Albert Talbot, who watches through binoculars everything that goes on in the town. As a former spy, he has been trained to observe rather than to live. One could say life has passed him by, except that he's seen it all.

The community, unlike the coast on which it lives, is not immediately attractive. Women are too often sexual objects, rearing unpleasant children. "Children are crap," remarks Merridy's cousin and friend Tildy, wrestling with her unprepossessing brood. If the reader was worried that Merridy's wistful longings were verging on the sentimental, Tildy is perhaps reassuring. However, these small-town lives do sometimes degenerate into soap opera. The opening seems to hold the sea at bay as it focuses on small-town rivalries in machismo and sexual relationships, before showing us unequivocally why we should care. The sea always comes in again and washes away the trivia, but sometimes it takes a little too long to make its appearance. Engagement with the sea, and its significance in the unplumbed depths of the human psyche, is the real, undoubted strength of this novel.

Harvill Secker £17.99 (402pp) £16.19 (free p&p) from 0870 079 8897

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