The Department of Transport confirmed last night that Valentia is to be scaled down as a major marine rescue co-ordination centre in the next five years.
The announcement has been greeted with anger and concern about loss of permanent jobs on the island, internationally known as the location for the original transatlantic cable station which linked Europe and the US.
The department confirmed that two national marine rescue co-ordination centres are to be established "against a background of renewed investment and support for maritime safety".
The decision was being taken because much of the equipment at the three Irish Coast Guard Centres - Valentia Island, Malin Head and Dublin - is in urgent need of replacement, it said.
Valentia or Malin would not be closed as Coast Guard stations but their precise function had yet to be determined, the statement said. Although it has not been confirmed, it is expected new centres will be located at Drogheda on the east coast and at Galway or Ennis on the west coast.
The decision would not put lives at risk, Mr Dempsey told Radio Kerry amid a storm of criticism in the county.
One lifeboat operations manager said more Coast Guard stations, and more rescue marine centres, not fewer, were needed.
The Valentia Marine Rescue Centre, perched dramatically on the Atlantic edge of the island, has survived two previous attempts to shut it and last year seamlessly took over the functions of the Dublin Coast Guard when works had to be carried out at that station. There was a sigh of relief locally that the station would survive.