EFFICIENT means of communication at sea between life-boats and aircraft have been of growing importance in recent years. Particularly vital is the link be- tween life-boats and helicopters, for the number of services in which life- boats and helicopters co-operate has been increasing rapidly. In 1961, for instance, the number of such services was 57; in 1962 it was 141.

Until a few years ago the methods by which the coxswain of a life-boat and a pilot of a helicopter communicated at sea were somewhat cumbersome. Any call had to pass through the G.P.O.

coast station, the coastguard and the aircraft's base. An important change occurred in 1956 when the Institution decided to install very high frequency radio telephones. As a result there was a direct link at sea between helicopter and life-boat, and the value of this link has been proved over and over again.

Much Less Interference The helicopters which normally take part in sea rescue operations are all provided by the Royal Navy or the Royal Air Force, and the Services are now abandoning the very high fre- quency of 123.1 m/cs., which has hitherto been in use. Instead they are commu- nicating in the ultra high frequency band. Their calling and distress fre- quency is now 243 m/cs., and the "Search and Rescue - Scene of Action" frequency is 282.8 m/cs.

The ultra high frequency sets are much less subject to interference and voices are heard more distinctly. The R.N.L.I. has therefore decided to make the same change from very high fre- quency to ultra high frequency as the Services have done, and a contract has been entered into for the hire and main- tenance of 170 ultra high frequency sets.

They will be fitted in all life-boats in the active and reserve fleet. The annual cost will be £15,000.

Harbour Control and Radar Service Another important decision which has been taken by the Institution is to install very high frequency (frequency modulation) equipment in a number of life-boats. The International Maritime VHF/FM band is now being used extensively by shipping for communica- tion with certain shore stations as well as for harbour control and radar advi- sory services. The number of life-boats within range of such shore stations is limited, and at present 25 life-boats only can be fitted with the VHF/FM sets. H.M. Coastguard and the Institu- tion's life-boats will also be able to com- municate on Channel O (156.0 m/cs.).

These new and important forms of communication do not mean that the existing medium frequency radio tele- phones fitted in all life-boats are out- dated or can be dispensed with. These sets will continue to be used for the passing of all messages in services in which other shipping is involved. The VHF/FM sets will normally be used only when inshore rescue services which do not call for the help of other shipping are being carried out..