Highland's geography adds a few problems of its own. There are only 37 primary supply teachers available in Caithness and Sutherland and 42 in Lochaber.
"We have enhanced management time for primary heads and this has created further demand for supply staff," Mr Robertson says. "Next year there will be even more staff development opportunities in primary and secondary."
The council is piloting the use of permanent supply teachers and has recruited six each in Caithness and Lochaber, attached to specific schools. They are largely teachers just out of college which Mr Robertson admits is not ideal.
"It does give them an opportunity to work in a number of different environments but we will limit them to two or three schools," he says. "Pupils will have the advantage of knowing the teacher and there will be far less disruption to teaching and learning."
At present officials estimate heads have often to spend an hour on the phone in the mornings trying to get staff. "In the rural areas they are fishing from the same pot," Mr Robertson says. "We have also encountered difficulties recruiting Gaelic-medium primary teachers, although this is a national problem."
In the secondary sector, some subjects can present problems and there are no easy solutions because of the distances teachers have to travel. There are 466 names on the supply list.
Highland ran a media campaign in May to encourage teachers to join the supply lists. It is also running a course for returners this session. Eventually it hopes to establish a computerised online supply list.