And the portrait that emerges is of a very sad figure; one who, as the end neared, knew his gift was ebbing and his mind was going, and who eventually sank into destructive and paranoid depression. It's a story that famously ends with a shotgun suicide in Ketchum, Idaho, in 1961 - one of a string in the family; suicide stalked the Hemingways like a game hunter (Ernest; his father, Clarence; his brother Les; his sister Ursula; and possibly another sister, Marce).

It's also a story, Hendrickson says, of great bravery. And he's not talking about beasts in the African jungle but Hemingway's stoic determination to continue writing, almost until the end. Only in writing did Hemingway find release from the destructive depression that gripped him more and more as mind and body fell apart.

In this sense, Hendrickson counters the assumption that Hemingway became a parody of himself and that his writing reflected this. Not only did he produce work such as A Moveable Feast (the lies and misrepresentations notwithstanding, it is still a vivid picture of Paris in the '20s) and the generally acknowledged classic, The Old Man and the Sea, he was also in a very real sense writing for his life. And, Hendrickson adds, writing about living life and engaging with life.

But in 1934, when Hemingway first sailed the 42-foot cruiser Pilar into the Cuban waters after he moved to Havana, the Mayo Clinic, the shock treatments, the paranoid delusions and death were still far away. Characters such as Arnold Samuelson, who sailed on the boat with him and whose writing he encouraged and supported, enter the story. As does a US Foreign Service official in Havana, Walter Houk (whom Hendrickson interviewed many times) and his wife Nita (with whom Hemingway was infatuated); legendary game hunter Bror Blixen and his wife Eva (with whom Hemingway probably had an affair); and the young Venetian woman Adriana Ivancich, the muse of his later years. Add to this the recollections of sons Jack, Patrick and Gregory and figures such as Maxwell Perkins and Scott Fitzgerald and there are stories aplenty. Arguably, too many. Hendrickson goes into their lives in far too much detail.

Hemingway's treatment of them all is often erratic, from the generous and kind to the mean and nasty. But whether he emerges favourably or otherwise is not the point. The test of a literary biography is the extent to which it illuminates the subject's writing. The fresh angle is use of the boat but the degree to which this motif is informative is arguable. Often the strategy works but there are times when it creaks. Looking, for example, at the longer, ''loosened'', more complex and free-flowing sentences Hemingway used in later writing, Hendrickson says, ''I believe Pilar was a key part of the change, allowing him to go farther out, where you don't see the shoreline''. It might just as easily, and more plausibly, have been Hemingway's readings of Proust.