Dotted around the globe, from the Central American jungle to the heart of industrialised Germany, there is a breed of schools unlike any other: the entire pupil population can change overnight, key stage test results never make it to a league table, and if Greek is on the timetable, it's more likely to be the modern rather than the ancient version.
Service Children's Education (SCE) provides schooling for thousands of children of armed forces personnel posted overseas, with 43 schools in 10 countries. For Louise Watson, it was just what she was looking for.
Louise, 29, had spent some time working in America after qualifying as a teacher and she applied to SCE almost as soon as she returned to the UK.
Two years later, she was heading for a new life in Germany.
"I love living and working abroad," she says. "I'm young, I've got no ties - I can travel and pursue my career at the same time."
For the past year and a half, Louise has been teaching at the Lister School, in Herford, near Hanover, where she has a mixed class of Years 3 and 4. The content of the curriculum is the same as in the UK - although lessons involving money are likely to be in euros as well as sterling - but she says there is a marked difference when it comes to the pupils.
"The children are used to moving around and have this ability to socialise and make friends very quickly. They're much more adaptable and less anxious than children in the UK," she says. "They're also very open and like to talk about how they're feeling. If they are anxious, they tend just to tell us."
Lister, a school of around 240 pupils, is in the middle of a British Army barracks. Louise lives off the camp in an Army house within the German community. Under Ministry of Defence rules, her boyfriend can visit, but cannot move in unless they get married. "You have to accept the Army's rules and regulations," she says. "Everybody is supportive and friendly, but there are times when it's like a goldfish bowl. I'm very independent: I go to the local gym, to aerobics and salsa classes and meet Germans, though on the whole, the British tend to stay with the British. Some people probably wouldn't enjoy everyone knowing where you were on a Saturday night."
Her grasp of German was virtually non-existent when she arrived but a "buddy" allocated by the school helped her set up home, including getting her telephone connected and opening a bank account. She is learning the language along with her pupils.
Louise says career factors played a role in her decision to apply to SCE.
She is now her school's special needs co-ordinator and inclusion manager, is on the leadership team and is studying for her National Professional Qualification for Headship. "I'm working my way up, although I know there will come a time when I will have reached my limit here," she says.
Transience is one of the biggest challenges facing SCE schools, says Kathryn Forsyth, its director of education. Many postings last up to two years and if an entire regiment moves, 80 per cent of a class can change overnight.
"The priority for us is to get to know the children quickly," she says.
"It's not just the ones who move who are affected; the pupils who stay find their friendship base changes."
To try to ease the transition, she says they liaise with the schools new pupils are coming from, allocate "buddy" children when one pupil arrives in the middle of the school year, and designate a "friendship" child for anyone struggling to adapt.
David Wadsworth, SCE chief executive, says the schools are often focal points for the local forces community, particularly when one parent is on active duty and the other is left at the camp without an extended family on hand for support.
While some teachers make a career out of working for SCE, others only stay for a fixed period. Turnover is around 10 per cent, with teachers only posted to the more remote schools if they have already worked for SCE.
"For those who don't stay long, it is often their first experience of living overseas, away from their family," David says. "It can be lonely if you are not a social person."
He says SCE runs an extensive programme of professional development courses, funding teachers to return to England, or flying the lecturers out to Germany if there is sufficient demand.
Peter Kerr had only planned to stay a year when he joined SCE, then the British Forces Education Service. But 27 years later, and on his third headship, he now has no thoughts of returning to work in the UK.
After starting in Germany, then on the front line during the Cold War, he is now at Episkopi School in Cyprus, which has become the front line since he arrived in 1999. The school currently has 383 children, although it can take up to 460. Peter, 54, calculates there were 1,030 pupil changes between October 2002 and October 2006.
He does not have the same autonomy as his counterparts in the UK. Budgets are largely held centrally and, with teachers appointed to the agency rather than the school, he has less say over recruitment, although he has had candidates flown over to Cyprus for interview. "But generally speaking, our schools are well stocked and well supported," he says.
Like all SCE schools, Episkopi has well-established procedures in case a child's parent is injured in action - an increased possibility with the extensive deployment of British forces in Iraq and Afghanistan.
"We have a regiment here that is going to Afghanistan in April, and that can cause anxiety and uneasiness among the pupils," says Peter.
"Our location places demands on the soldiers and airmen, and we must provide stability and calmness to allow the children to prosper."
Next week: Inside a military school in the UK
PUPILS ON PARADE
The demographics of the Armed Forces mean that Service Children's Education is predominantly a primary school organisation.
Of its 43 schools, only six are secondary - four in Germany and two in Cyprus -and it has twice as many five-year-olds as 11-year-olds.
Armed Forces personnel with secondary school-age children posted to a country where there are no suitable SCE facilities can claim a subsidy for boarding school places in the UK.
SCE schools have about 13,000 children and follow the national curriculum of England and Wales, even though some of the pupils will come from and return to schools in Scotland and Northern Ireland.
SCE employs 738 teachers, plus supply teachers, and has average class sizes of 20 in primary, and 16 in secondary.
SCE follows the England and Wales School Teachers' Pay and Conditions Document in most areas, although for maternity, sick pay, and grievance and disciplinary procedures, it follows Ministry of Defence policy. Additional allowances are available for living overseas.