IN THE DISTANT PAST, mariners venturing into unknown waters were as afraid of sea monsters as they were of the natural elements. And there are so many convincing accounts of sea serpents in particular that it now seems astonishing that they seem to have been a myth all along.

Or perhaps not, of course. In this book Bob and I examined some of the more famous encounters and also look into some of the deeper myths, like those of Leviathan, the Midgard Serpent and Quetzalcoatl; plus anything else of interest that turned up.

In this book there is probably more attention paid to the possible physical reality of the creatures than in, say, the Book of the Unicorn, but the reality aspect is fascinating anyway and I've done time at Loch Ness watching the misty morning waters in hope of a glimpse. In fact as a child growing up in Africa I once believed I found an unknown water monster in the Zambesi.

One day, when eleven or twelve years old, while crossing a fallen tree to an island half a mile or so upstream from the Victoria Falls, I happened to spot what looked like the back of a creature in the stream below. I knelt down on the tree for a better look. Sure enough, its outline was clear against the stream bed, about three feet wide and marked with cell-like divisions like the back of a turtle. I could only see a foot or two of length though, because of tangled branches. There were river turtles in the Zambesi but none growing over a foot wide as far as I knew. I ran to my sister and her teenage friends on the bank with the news but the boys' (being teenage boys) response was to grab all the rocks and branches they could find and lob them at the spot I pointed out. A minute or so later in a pool downstream of the natural bridge I briefly saw two nostrils, about three or four inches apart, break the surface. Then they submerged and after that nothing.

A few months later I went back with just my mate Michael O'Connell and the creature was back in its original place in the stream below the fallen tree. Not wanting to disturb it, we cycled off to the nearest phone several miles away and rang a friend of my parents, who headed the government department that looked after the river. But of course he just thought we were a couple of overexcited kids and certainly wasn't going to take our word seriously enough to get in a Land Rover and come and see for himself.

When we went back to the spot, the creature had gone so we had not even the option of prodding it with a stick to see what it was. With hindsight it was very unlikely to be a turtle because I've not heard of any that size being found in that part of the river in the 30-odd years since. It wasn't a crocodile because I was familiar enough with their back-markings and anyway it was too close to the Falls (or so we fondly believed as we went swimming around there). It may parhaps have been a large iguana type lizard called something like a leguaan in Afrikaans, apart from the cell-like markings which I could see quite clearly . . .

Anyway, this little mystery was the viewpoint from which I addressed this Book of Sea Monsters, which also in fact covers some of the more famous lake monsters, but it seemed a shame to complicate the title. Below are thumbnails for three stories we included in the book.