Communications

While radio communication was being developed in the 1890s, merchant and naval ships still depended on visual signalling. Coastguards were expected to read/send 18 words per minute with semaphore flags and 10 with a flashing lamp, the new acetylene fuel extended visibility to 12 miles. By the First World War telephone lines linked coastal stations and Coastguards were operating wireless with ranges from 100 to 1,000 miles.

From 1923 the Board of Trade saw improving communications as a key task. The old station to station telephone line was replaced with the Post Office system. The telephone now immediately informed Divisional officers of events, including the need to set bad weather watches at intermediate stations, and was used to alert the RNLI.

In 1951 it was recommended that visual watching should target vessels under 500 tonnes as larger ships should have radio and could be monitored by a listening watch. By the mid 1960s many Coastguard stations used VHF radio for direct communication with lifeboats, inshore rescue boats and Coastguard vehicles. Within a decade the whole Coastguard communication system of MF and VHF radio, telex and telephone was reviewed, and by 1974 stations were able to maintain a listening watch on VHF covering nearly all UK waters. Responsible sailors around the UK inform the Coastguard of the details of their voyages, radioing in on departure and arrival.

The Coastguard became a '999' service in the 1960s enabling the public to raise the alarm as it does for other emergency services. With the advent of the mobile telephone, Coastguards can now be quickly alerted to emergencies even when radios are not available.

Satellite technology has revolutionised radio communication and navigation. Vessels can determine their position on the globe within metres.

By international agreement all merchant ships over 300 tonnes carry communications which link directly to the Global Maritime Distress and Safety System (GMDSS). These transmit automated urgency or distress signals as digitally encoded bursts, which assist clarity, and are received by computers in Coastguard Maritime Rescue Co-ordination Centres (MRCC). The signals relay the vessel identity, location and nature of the alarm. As a result of GMDSS Falmouth MRCC has supported communications for search and rescue as far off as the South Atlantic. All vessels can also carry Emergency Position Indicating Radio Beacons (EPIRB) whose signal quickly reaches the Coastguard and so triggers an emergency response.

The Coastguard co-ordination centres are being fitted with Integrated Coastguard Communication System (ICCS) which has replaced analogue communications with digital technology.

The ICCS enables MRCCs to share the workload during major incidents or to release staff for other duties. In line with improved communications since the 1930s this new technology has reduced the number of stations manned by full time Coastguards.

In 1999 the Coastguard replaced British Telecom in providing Maritime Safety Information. Four-hourly meteorological and navigational warnings are broadcast using VHF and MF with a coverage out to 150 miles. The Coastguard also links vessels at sea with medical authorities so that advice can be received directly from a doctor.