Emergency calls are being redirected to staff in Belfast and Stornoway, with even routine ones now being handled by staff in Northern Ireland.
The move, which is ahead of its planned closure on December 18, has angered members of the Coastguard SOS Campaign, set up to save eight stations being axed as part of UK Government cuts.
Holyrood Transport Minister Keith Brown has branded the move a "potentially dangerous experiment".
Other centres to close include Great Yarmouth, Liverpool, Thames, Swansea, Brixham and Portland. Clyde and Forth stations are earmarked to close by the end of the year.
However, a document leaked to the campaign appears to outline details of the change.
It outlined the closure of Clyde, but also suggested the work to complete the "aerial transfers" to the coastguard in Belfast and Stornoway was due to be completed by last night.
Campaigner Dennis O'Connor said: "This further development shows there is an apparent desire by some to rush through the closure plan and we urge Members of Parliament to ask the Secretary of State for Transport to investigate the tactics that are being employed by his departments."
A Maritime and Coastguard Agency spokesman said: "This handover period has been planned for some time. All the staff have been informed well in advance."