V.H.F. for small boats

Press, 19 August 1981, Page 27

V.H.F. for small boats

Whether it be in the air. on the land, or at sea. radio communications in one form or another has become an essential aspect of modernday life. At sea. for example, communications used by ships over the past half century have included flashing lamps, flags, and more recently, radio in one form or another.

Ocean-going shipping for some years has used highfrequency radio communication, using what is known as “double sideband” transmissions.

As more efficient and effective means of radiotelephone communications were developed, the airwaves became more cluttered and an international agreement arrived at to require “single sideband” operation. In addition, many vessels use radio teletype and very high frequency (V.H.F.) communication and also satellite communication.

1 Coastal shipping generally uses similar communication systems which are, however, specially designed and operated on frequencies which give the best performance in the area around New Zealand. More and more coastal vessels are beginning to use V.H.F. communications as are local port authorities. Whereas many small vessels, including fishing boats and yachts, for years used World War II surplus equipment, all are now faced with

comforming to the new single sideband regulations. Such equipment is available in the range from $2OOO to $16,000.

While such an outlay may be relatively insignificant for large ships. it can be prohibitive to the small boat owner who may just wish to sail around the harbour and in and out of nearby bays.

Some small boat owners have resorted to using Citizen Band radio but the efficiency of such sets is rather limited in bays and around islands.

Many boat owners are looking towards V.H.F. radio for their communications as in Auckland where a talkthrough system has been installed to cater for the large number of vessel movements within the inner harbour.

Such a system requires the use of a repeater station installed at a high elevation because V.H.F. communication operates on the line-of-sight principle. Recently, the Banks Peninsula Cruising Club, along with other interested parties, has done extensive field sight testing to look into the economic feasibility of installing a local V.H.F. repeater service for the small boat owner.

Field tests were very satisfactory and, at present, the club is negotiating with the Post Office for permission to install such a service. No such permission has yet been granted.