Technology superceded by modern nav aids

The Maritime and Coastguard Agency (MCA) have announced that its shorebased VHF direction finding (DF) facilities will be discontinued from the end of this year.

DF allows the coastguard to operate an aerial and discover the bearing of vessels in-range that are transmitting on VHF. The symbol above indicates the aerial’s position on a chart.

But the MCA has decided that the service is no longer needed as it is ‘now available on all mobile search and rescue (SAR) assets’, such as GPS, DSC and EPIRBs.

Cost is another deciding factor, as replacing the current, outdated, shorebased DF infrastructure would have £8m captial costs and £16m support costs over 10 years.

The Channel Navigation Information Service, which monitors all shipping in the Dover Straits, will be the only Maritime Rescue Co-ordination Centre (MRCC) to retain its shorebased DF facilities in 2011.

The MCA insists that the withdrawal of the service will not negatively impact SAR capabilities as mobile DF will still be in operation.

According to the International Aeronautical and Maritime Search And Rescue manual, a MRCC must have DF before it can take responsibilty for a SAR region.

However the facilities can be either shorebased or mobile and the manual warns that the reliability and availability of the shorebased network is often the service’s weakest link.

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