Last month the service's board voted to cut the number of its control centres from eight to three, with only Johnstone in Renfrewshire definitely secure.
The other two will be chosen from Edinburgh, Dundee, Aberdeen and Inverness following a consultation and further investigations over the next few months.
Even before that meeting, the leader of The Highland Council, councillor Drew Hendry wrote to Pat Watters, chairman of the board, to express his deep concerns about any proposal to close the Inverness control room .
Now Orkney is also highlighting the importance of the Inverness control room staff's detailed knowledge of the Highlands and Islands and how it plays a vital role in saving lives.
Convener Steven Heddle and the chairman of the council's police and fire sub-committee, councillor Andrew Drever, have written to Mr Watters.
Mr Heddle said: "The experience and knowledge held by Inverness control room staff is immense and has been acquired over a long period. These operators are integral to the community they serve. They have a vast understanding of the Highlands and Islands - an area often described as the size of Belgium.
"It's an area of great diversity in terms of geography, dialect, the Gaelic language and the duplication of place names throughout Shetland, Orkney, the Western Isles and Highlands. The knowledge and expertise of the control room staff ensures the response to fires and other emergencies across the region is second to none."
Mr Drever said: "This knowledge extends to the location and availability of other key resources such as ferries, lifeboats and council pilot launches. Getting the right resources to the right place at the right time gives the best chance of saving lives."