The secret of his success, as he sees it, is quite simple. He gives teachers what they need to structure a reasonable lesson and he provides children with lots of pictures, games and activities to hold their interest.
Geography, particularly in lower years, is often taught by non-specialists, deputy heads, teachers from other departments - busy people who are filling in and without the time to prepare as they should. Waugh takes this on board: "I have tried to write something so that the cookery teacher - I know they shouldn't be called that - doing two or three periods a week can manage."
So what does the "cookery teacher" need? One or two large photographs, bite-sized pieces of factual content, a map and some activities on a clearly-designed double-page spread - the right amount to fill a lesson and fulfil the requiremen ts of the national curriculum. It's a step-by-step formula that works. Children like it and teachers feel secure with it.
Sales of Waugh's Key Geography series published by Stanley Thornes, which caters for children at key stage 3 and 4, have now passed 1.3 million copies, making it the most popular national curriculum series in print. When you combine this with the popularity of his GCSE book, The Wider World and his A-level book Geography: An Integrated Approach (Gaia), both published by Nelson, then the extent of his empire appears truly remarkable.
Nelson is considering sending out a free portfolio of fact sheets to schools using Gaia, updating the figures in the book, so prolonging its shelf life. The UK and Europe will be published in time to cater for the 1998 GCSE syllabuses.
David Waugh remained a geography teacher for 30 years, but the demands of writing - and an assurance of a "comfortable" income for the rest of his life - prompted him to take early retirement in 1992 as head of department at Trinity School, Carlisle, a post he had held for 20 years. It is this prolonged experience on the shop floor which he believes has helped him to understand the needs of teachers and the psychology of children.
I always imagine that I am talking to my class when I write these books, and I know that if I explain something in such and such a way, that little group over there won't know what I'm on about - I have to put in things that will interest them, that will hold their attention. People do say that children identify with the books as if I am talking to them."
He describes himself as an "enthusiastic traditionalist" teacher, believing he had to earn his keep by disseminating facts. His involvement in the Schools Council Avery Hill Project in the 1970s led him to look at more issues-led, child-centred methods, but he believes his books reflect pretty much his style of teaching.
Now he works at home, his beloved Roxboro, where he has lived for the past 25 years with his wife and two sons and which stands alone near the village of Castle Carrock 10 miles from Carlisle. In one direction he can view the sweeping fells of the Pennines, from another the Lake District.
Although Waugh now travels extensively abroad, he had not been outside the UK until 10 years ago. It was family holidays in the Lake District which gave him his real love of geography, and a family background where maps and naming places were very much part of routine. On his fourth birthday he asked for an atlas.
He was brought up in Newcastle upon Tyne and spent much of his early childhood with grandparents in Wallsend. His father fought in the Second World War and his grandmother had a map on the wall to identify places in the news. Young Waugh collected stamps and flags, and quizzes about places and capitals were a regular feature.
A mild-mannere d, personable man David Waugh nevertheless conducts his writing like a military campaign. When you dissect his methodology it is easy to see why he has been so successful.
His Key Geography: Foundations came out in 1991 at a time when the geography Orders for the national curriculum had been issued, when teachers were faced with trying to make sense of hundreds of statements of attainment, and practically nobody could work out how they were going to create reasonable schemes of work .
Waugh, who was already successful with his O-level book The British Isles,published in 1983, pitched in where others feared to tread. Teachers were panicking and he cut a path through the maze, producing Key Geography the summer before the curriculum came on stream. It gave teachers time to digest and prepare. Leaving the confusion of attainment targets to one side, Waugh went straight for the content, dividing it into manageable sections and producing a three-book series which covered 17 units over three years. It was the only textbook to cover the national curriculum at that time and everybody went for it. He has never looked back.
His chief priority, he says, has always been to help teachers. As we sit in his kitchen over mugs of tea, he brings out a chart showing how he prepared The UK and Europe. Taking all the different exam syllabuses and all the topics covered, he works out the common core topics. Those are the ones that go into his book, each covered by a double-page spread. He makes sure that a synopsis of the book is ready for the Geographical Association conference and that it is published by June, again in time for teachers to read it and prepare over the summer. It is all intended to make the teacher's life as easy as possible.
"So many geography books have been written by people who have written about what they wanted to write about - whether it has any relevance or not. Educationally they might be far better than mine, but I am thinking about the teacher," he says. Such is Waugh's influence that research projects are now beginning to look at the influence his textbooks have on geography teaching.
Indeed, the School Curriculum and Assessment Authority has commented on Waugh's work in a series of confidential reports on subject textbooks which include geography. He is aware of his critics: "HMIs have been critical of my books, they say they are too structured. SCAA says I have killed off innovation in teachers, that they don't have to think for themselves. They say Key Geography fails to challenge bright children. We think that is very unfair.
"Our teacher's guides are there to get people through the basics. We expect them to gather their own local material. I would always have taught above this standard, I always gathered my own material. But if teachers don't find their own examples, is that because they are lazy or incompetent or is it because they have many other commitments and simply don't have the time?
"When I was teaching, finding resources was the difficulty, not creating activities. What is so sad is that so many teachers lack the confidence to produce their own questions and activities."