Leviathan or, The Whale, By Philip Hoare

Philip Hoare is obsessed with whales. Not only that, he's obsessed with a fictional character, Captain Ahab, obsessed with a fictional whale, Moby-Dick; plus he's obsessed with the writer, Herman Melville, who created that landmark of American literature.

This scintillating, scattershot, blunderbuss of a book sees him examining all of these obsessions, following in the real-life footsteps of Melville, the literary footsteps of Ahab and the watery fluke-splash of numerous whales, as he details man's complex and often contradictory relationship with these leviathans over the ages.

Leviathan or, The Whale is an impossible book to categorise. It starts with memoir, Hoare describing his formative encounters with a killer whale at Windsor Safari Park, and a sad-eyed beluga whale in a Coney Island tank. From there we get large swathes of biology, history, social commentary, travelogue, literary criticism, biography and personal observational stuff which verges on the spiritual at times.

It shouldn't all work together but it does. Throughout the book, Hoare's unbridled enthusiasm for his subject is infectious. But this is no gushing soliloquy on the wonders of the world's largest animal. Hoare has clearly done a huge amount of research into his topic, and it acts as an anchor which stops the writing, in his more fanciful moments of exploring the myth and mystery of whales, from swimming off into the briny deep.

One of the most remarkable things to emerge from this book is the fact that we still know so little about whales. It was only in the 1970s, after man had walked on the moon, that a whale was even photographed underwater in its natural habitat. Even now, there are vast gaps in our knowledge of whales' methods of communication, social structures, migration patterns, hunting techniques and mating habits.

And yet this book is filled with fascinating nuggets of information on virtually every page. For example, recent research on elusive bowhead whales has found specimens which are well over 200 years old, and the current scientific thinking is that we have vastly underestimated the life span of whales in the past. Imagine, the same whale that inspired Melville to write Moby-Dick in 1851 could still be cruising the oceans today.

Or, did you know that if a narwhal loses its tusk, another narwhal will break off the end of its own tusk in the wound to reduce its compatriot's pain? Or that a sperm whale eats one hundred million tons of fish a year, including whole sharks and giant squids? Or that the heart of a blue whale is the size of a car?

The biological facts of whales are overwhelming, as is the extent of man's whaling industry over several hundred years. Hoare travels extensively around former hotbeds of the industry, mostly on America's eastern seaboard, from Nantucket to New Bedford, Cape Cod to Provincetown. These sections manage to mix astute and perceptive travel writing with history, as the author details the huge scale of the enterprise: hundreds of ships harpooning thousands of whales a year for more than 200 years. Hoare is unflinching but non-judgemental in his accounts of the trade. Shockingly, the number of whales being killed each year reached a peak as late as the 1950s, and it was only in the 1960s that the tide of public opinion began to move in favour of the conservation of these magnificent beasts.

Partly, that was down to the ubiquitous nature of whale products. Used for everything from lighting to lubrication to clothing, whale products remained much in demand until very recently. Indeed, the main perfume manufacturers still use ambergris, a strangely unctuous substance created in whales' stomachs to assist the passing of giant squid beaks, in creating their latest scents.

In visiting these whaling ports, Hoare is also seeking to get closer to Melville, who sailed on whaling ships as research. Hoare spends a long time discussing Melville and his famous book, but it's never laborious or tedious literary criticism; more an enthusiastic critique of the idea of whale as metaphor, as myth, as eternal mystery. These sections are also full of interesting asides and small revelations, such as the fact that Turner's enigmatic whaling paintings were a big influence on the direction which Melville's book eventually took.

Like anyone discussing his or her obsessions, Hoare tends to go over the top at times, most obviously in the sections in which he concentrates on his own relationship with whales. His tendency towards anthropomorphism, hyperbole and mysticism is excusable at first but ultimately a little jarring.

His quest to get closer to whales is physically successful but mentally less so, as he concludes that these vast and emblematic creatures of the deep are essentially unknowable to humans. Nevertheless, as a byproduct of that obsessive quest, this thoroughly engaging, rigorously researched and often revelatory book is a joy to read and one which Melville, surely, would have appreciated.

Doug Johnstone's latest novel is 'The Ossians' (Viking £12.99)