They have formed an action group to fight what it regards as Shetland Islands Council's "raid on rural education", which it believes will hasten the erosion of life in their communities.
In a move to underline their feelings about the impact of the proposals, the group launched six "St Kilda mail boats" on Saturday carrying campaign banners to evoke the sense of desperation felt by the remote community of St Kilda. In the 1890s people living on the remote archipelago, which evacuated in 1930, enclosed messages in waterproof vessels tied to homemade buoys and cast them in the sea in the hope they would be found.
Gordon Thomson, spokesman for campaigners Communities United for Rural Education, said the proposal ran counter to the council's own policy of supporting island communities.
"There is a genuine sense that rural and island communities will be decimated if our schools and transport links are removed," he said. "We feel that this will be the unintended consequence of the council's current policies and in direct opposition to their own corporate plan."
He added: "The abandonment of St Kilda happened. The clearances in Shetland happened. And some of our current communities are on the brink. They are not mythological events. People are genuinely alarmed by these trends."
Shetland Islands Council plans to close the Out Skerries Junior High School, which has just three pupils, on July 4, saving £73,500 a year but causing the pupils to commute each week to Anderson High School in Lerwick during term-time and stay in a hostel attached to the school.
It also wants to close the third and fourth years at five other junior highs and ask pupils aged 13 and 14 to transfer to Anderson and Brae High School, also on the mainland, at the end of second year.
While the children transferring from the junior high schools on the main island, Sandwick Junior High and Aith Junior High, would have longer daily commutes, pupils on the outlying isles, at Whalsay Junior High, Mid Yell Junior High and Baltasound Junior High, would have to travel from their homes on Sunday night and stay all week at hostels.
Brodie Lawson, 15, chair of Mid Yell Junior High School Pupil Council, said: "It might not seem like a big deal to some people, but for us to leave our homes, our families and our communities at 13 or 14 years of age is too high a price to pay."
Councillor Malcolm Bell, convener of Shetland Islands Council, said the authority faced huge financial pressure and that the current system of secondary education could not be sustained.
He said: "We have been living beyond our means for too long. We had a pot of money in terms of oil revenue and we have dipped into that over the years. At one stage we were over-spending by around £35 million a year."
However, he added that the purpose of the plans was not solely financial, with education experts advising that if pupils had to transfer, it was better they do so at the end of year S2 rather than at the end of S4.