Robert Kunzig's book - Mapping the Deep, The Extraordinary Story of Ocean Science - had been regarded as something of an outsider. But the story of jellyfish, siphonophores, salps and other strange characters from the world of water clearly enthralled the judges.

They honoured Kunzig, an editor for Discover Magazine, with a cheque for �10,000 at a gala dinner in London's Science Museum on Tuesday.

The Aventis Prize for Science Books - sometimes dubbed the scientific community's Booker Prize - has been running since 1988. It also has a junior prize for the best book aimed at children, which this year went to Michael Allaby for the DK Guide to Weather (Dorling Kindersley, �12.99).

Passionate writing

Sir David Weatherall, of Oxford University, chaired the panel judging the main prize.

Robert Kunzig is the European editor of Discover Magazine

He said of Kunzig's publication: "This book opens up a whole new world in a passionate, revelatory and scientifically rigorous way. It makes the mysteries of the deep sea really exciting."

Mapping the Deep (Sort of Books, �8.99) is described as a state-of-the ocean report on the sea and its science.

It starts with an account of the chemical properties that make water "special stuff". It then makes the link between exploration of the deep and outer space. Mapping the Deep also introduces us to some of the bizarre creatures that live many kilometres down. And it details just why the oceans are crucial to the health of the planet.

Robert Kunzig draws on the voices of oceanographers past and present - scientists, pioneers, maverick thinkers, deep-water divers and submersible pilots - to tell his story.

Revolution in understanding

He told BBC News Online: "I was amazed just how little we knew about the oceans - but at the same time what a revolution there has been in the past few decades in our understanding of marine science.

"I was just trying to get that across in a way that would touch a wide audience. It is very like space exploration - the only difference is that for some reason space exploration seems to get more attention. People can stand out in their backyard and look up at the stars; looking at the deep is a whole lot harder. We have to rely on the oceanographers to do it for us."

The Aventis Prize will mean Mapping the Deep is sure to get a high profile in shops in the next few months. It will also bring huge recognition to Kunzig himself and possibly lucrative writing offers. Last year's winner, superstrings expert Brian Greene, is reported to have received a $2m advance for his next book.

Kunzig is the European editor of Discover Magazine, based in Dijon, France. His writing about the oceans has already won him the AAAS-Westinghouse Science Journalism Award, presented by the American Association for the Advancement of Science, and the Walter Sullivan Award for Excellence in Science Journalism, presented by the American Geophysical Union.

Other books that were shortlisted for the main prize:

Creation: Life and How to Make it, by Steve Grand (Weidenfeld & Nicolson, �18.99)

In Brief: Kicks off with a curious depiction of his wife's sleeping body and goes on to tackle science's big questions, like What is life?, while taking the reader on a cheerful whistle-stop tour of artificial intelligence and a highly personal view of the future for intelligent machines.

Author: Author of the computer game Creatures, managing director of Cyberlife Research and self-styled "Cybergod".

Malignant Sadness: The Anatomy of Depression, by Lewis Wolpert (Faber, �7.99)

In Brief: Clear and comprehensive guide to the science of severe depression, its causes and current treatments, with some personal touches from Wolpert's own experience of the disease. Concise and candid - you won't want to put it down.

Author: Distinguished biology professor at University College, London.

Mendel's Demon: Gene Justice and the Complexity of Life, by Mark Ridley (Weidenfeld & Nicolson, �20)

In Brief: Where else could you get a comparison of the merits of cloning, Earthly sex and Angelic sex? Ridley provides a colourful guide to why, biologically speaking, life is so complex. It is both thought provoking and hilarious, so that you can forgive the author his rare lapses into dry academic-speak.

Author: Influential evolutionary scientist at Oxford University.

Mendeleyev's Dream: The Quest for the Elements, by Paul Strathern (Penguin, �12.99)

In Brief: The Periodic Table could have been a lot more interesting at school with Strathern to explain its colourful history. He brings chemistry to life through some of its key characters through the ages from Paracelsus to Dmitri Mendeleyev and the unfortunate beheaded Antoine Lavoisier.

Author: Lecturer in philosophy and science at Kingston University.