BOOK REVIEW / Nautical knaves and forks: Anthony Quinn finds a salty atmosphere of unease in Candia McWilliam's latest novel - 'Debatable Land' - Candia McWilliam: Bloomsbury, 14.99 pounds

GREAT waves of memory pound against the margins of Candia McWilliam's new novel, threatening to swallow up its flimsy centre. Freighted with all kinds of anxiety and foreboding, the yacht Ardent Spirit is bound on a course from Tahiti to New Zealand, though for its three main characters the real journey is an interior one, back to their place of origin. That place is Scotland, and it takes a trip to the other end of the world to reclaim its significance.

The book's central consciousness belongs to Alec Dundas, an Edinburgh painter whose disaffection on terra firma has driven him to the sea. Two other Scots are on board - Logan Urquhart, the owner of the yacht, is the heir to a Scots-American fortune; Elspeth, his second wife, is a gentle, sensitive woman cowed by his brusque tyranny and the sainted memory of the first Mrs Urquhart. The rest of the crew comprises Nick and Sandro, benign and capable mariners, and Gabriel, an 18-year-old girl who has signed on as cook. Squeezed into unnatural proximity this disparate cast rub along together as best they can, and it is McWilliam's brief to monitor their various stirrings of attraction to one another.

The author's previous two novels, A Case of Knives and A Little Stranger, were famously larded with abstruse words, which merely added an exotic patina to a rather precious narrative style. Here, however, McWilliam holds such extravagance in check, setting a more muted, contemplative tone without sacrificing any richness of language. Her grasp of physical detail is immediately apparent. Describing the 'perfect nasal pitch' of Alec's mother, who in her time has gutted every type of fish, she registers 'the oily smell of herring; the salt-blood tang of mackerel; the gloom of cod; the washcloth vapour of cooked roes; the pipe-smoke and zoo smell of smokies'. Alec himself is sketched with witty concision: 'His black hair, red cheeks and white skin gave him the crisp appearance of a knave on a playing card.' No question, this writer is dealing from an impressively designed deck. Which is just as well, because very little seems to be happening on it.

Cut adrift from the conventional satisfactions of a plot, Debatable Land instead works to conjure a salty atmosphere of unease. As the boat meanders across the South Pacific, we begin to wonder what revelation the author is steering us towards. Are Alec and Elspeth going to wind up in bed together while running an errand for Logan? Will Logan seduce the waifish Gabriel below deck? And isn't that wind whipping up something fierce? Nothing much is resolved, because McWilliam has other more interesting fish to fry, directing our attention to Alec's childhood memories of Edinburgh, with its craggy austerity, sumptuous department stores, and brindled dogs. These reminiscences are clouded with melancholy, for the streets and squares of Alec's Edinburgh - like Logan's Glasgow and Elspeth's Borders village - have all but vanished, eaten up by the black jaws of development: 'The town that had been drained of a loch two centuries before was being drained of its own nature now.'

This is all marvellously done, so much so that the return from the past to the Pacific present becomes increasingly unwelcome. According to McWilliam, the sea provides 'an imprisoning gregariousness of heightened bourgeois anxiety', but the languid pace of the journey across it too often slows to a dead calm. Save for the grand finale of a savage three-day storm, the book's greatest moment of crisis comes when Gabriel's hand turns septic from a coral cut. Of course we're never likely to see the yacht under fire from a squadron of albatrosses, or menaced by sharks, because the drama of Debatable Land is nearly all in the mind. Yet the precision of language and the hawkeyed observation ought to be a complement to, rather than a substitute for, action. For instance, one is intrigued to learn that Logan 'was happy at a certain point with a woman, where he had found her weaknesses and remained unchallenged by her strengths', but there is not a single confrontation described to bear this out. We hear, but we don't see.

The result is a book that's easy to admire but rather difficult to enjoy. You can point to any number of incidental felicities and beguiling images - 'A pick-up went by, four children sitting in the back with a disdainful pig, the curl of whose nose showed him the most spoilt member of the family' - and still feel rather becalmed by the overall effect. McWilliam has kitted out a very seaworthy tub, assembled a fine crew and taken in some intriguing shoreline. Now all she needs is some wind in her sails.