For much of their teaching careers, Martyn and Paddy Powell have worked abroad - mainly in Germany, but with spells in the Middle East and Nepal. They returned to England this summer, after 26 years, so their 17-year-old son could sample life in Britain and a sixth-form college before university.
During their time overseas, they lived rent-free, received free heating and lighting, drove a tax-free car and earned the same rate of (taxable) pay as their UK counterparts, but with the added benefit of inner London weighting and a Pounds 1,200-a-month cost of living allowance.
"I've just been paid my first salary in England," says Paddy, now head of Buryfield primary school in Hampshire, "and it's substantially less than I was getting in Germany."
The Powells are among hundreds of teachers who apply each year for jobs through the Ministry of Defence agency, Service Children's Education (SCE).
SCE - based at the Wegberg military complex in Germany - provides schooling and other educational support services for children of service personnel and MOD civilian staff serving in the UK and overseas.
The agency has six secondary schools (four in Germany and two in Cyprus), four middle schools (in Germany and Gibraltar) and 45 primaries. Most of these are in Germany, with others in Cyprus, Brunei, Belgium, Belize, Denmark, Holland, Italy and the Falkland Islands.
Martyn Powell's first SCE posting - to Berlin - was in 1972. His last - from which he took early retirement - was a primary headship. Paddy, meanwhile, secured work as a locally entered teacher (LET) until she qualified for UK-based SCE status. Before returning to Britain, she was deputy head at a first school serving RAF Laarbruch on the Dutch border.
Teachers applying to SCE have to fulfil three criteria: they must be UK-qualified teachers with at least one year of teaching behind them; they must be British, Commonwealth or Irish citizens, or nationals of an EU member state; and they must normally have been resident in the UK for at least five years.
While some posts are advertised, primary teachers apply to join the "pool", which supplies 30 to 40 teachers a year. Initial appointments are usually for a fixed term of up to three years for teachers, five for headteachers. Most are to schools in Germany. But, as SCE points out, since the Strategic Defence Review, cutbacks in the armed forces overseas have led to school closures - from more than 80 to just over 50, with the number of pupils halving from 28,000 to 14,000. And with more cuts scheduled over the next four years - including withdrawal of the RAF from Germany - the agency is unable to guarantee further service beyond the initial term.
Career development is no problem for classroom teachers, says Paddy Powell. It only becomes a problem for those who want to move into senior management.
"There's an unwritten rule that people rarely promote within the same school once at senior management level. So you have to move. Or you decide to remain a classroom teacher because you and your family don't want to move. And if there are only 50 schools, there are only 50 headships. As deputy in a large first school, I had nowhere else to go. There were no headships coming up this year. So, if I wanted a career, I had to come back."
SCE includes an inspection and advisory service with specialist advisers and HM inspectors working to an Office for Standards in Education framework and timetable. It also has three teacher centres (two in Germany, one in Cyprus) covering in-service training and staff development. Paddy holds the national professional qualification for headship, achieved and funded through SCE.
"As professionals," she says, "you're never quite sure that what you're doing is accepted good practice because you're isolated from mainstream British education. But SCE mirrors best practice. And there's a solid work ethic abroad."
According to Paul Niedzwiedzki of SCE, the schools' national curriculum assessment and attainment results - and their pupil-teacher ratio - are also better than the national average. "We provide extra money for schools to match UK initiatives on literacy and numeracy," he says.
For Martyn Powell, one of the biggest advantages of working overseas was "exposure to teachers and children from a variety of geographical and social backgrounds. My teaching improved dramatically as a result."
Paddy agrees and adds that he misses the camaraderie and "the network".
They do, however, advise would-be SCE teachers to involve themselves in the local community and language. "You work in a ghetto where you educate British children and socialise with British people," says Martyn. "So you have to make an effort to go out into the community.
"On the education side, you have to accept what the army stands for, and understand it's very supportive to its own. Don't worry about the rank structure. The children are treated equally, whether a general's daughter or a corporal's. In that way, it's a great leveller."