A virtual school stretches over the Central North Island and has doubled its roll over the past four years.

The Volcanics eLearning Community lets "eTeachers" deliver to students who could be in a participating school from Ohakune to the Coromandel - or beyond.

A combination of video conferences, email, Google sites, Skype and text means the students can study subjects from a distance.

And the biggest user is Tokoroa's Forest View High School.

This year the Volcanics community has about 430 students studying one or more subjects, ePrincipal Sue Winters said.

The community covers 17 schools, including three in the Coromandel Peninsula which are new this year: Thames High School, Mercury Bay Area School in Whitianga and Coromandel Area School.

Schools generally joined for two reasons - "a wider range of programmes, and then also flexibility", she said.

"Where there are teacher shortages in subjects we'll often have a lot of students, for example level 3 physics and level three calculus."

However, other subjects such as languages, art history and accounting were in demand.

And Winters said students weren't missing out because they didn't get face-to-face teaching.

"We can build just as effective working relationships with our students online," she said.

"Our students become less and less dependent on hearing our voice."

Students have a once-a-week video conference for a discussion session.

"There might be between two and 10 schools dialling into one."

Between times their eTeacher would provide activities and help using online platforms such as Moodle or Google sites, or tools including Skype, email and even text messages. They're also supported by an in-school eDean.

And online inter-school communication was "the way that face-to-face teaching will go," Winters said.

"Even though students are in a school in a face-to-face classroom they will be connecting online with students in other schools and teachers in other schools to have a personalised, customised programme of learning."

It also prepared students well for the university environment, she said.

Forest View High School has about 65 students studying at least a subject through Volcanics. That includes foreign language options in the junior years and classical studies for seniors.

"We're able to maintain a very, very wide curriculum," principal Ian Ferguson said.

"If a student wants to take a particular subject but we may not offer it - but the student needs that for their particular pathway - rather than us saying 'Well, no you can't do that option' we try to make it happen through video conferencing."

It could also help students get around timetable clashes.

Independent, online learning could take some adjustment for students but Ferguson said it was "certainly not a poor option". "We're getting a lot of students achieving merit and excellence subject endorsements [in NCEA]."

Each school in Volcanics commits to run one programme online, and a Forest View teacher offers level three digital photography to the network.