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VHF Radio

The club has 4 VHF Radios, 2 hand helds and 2 fitted onto each Delta

Radio Procedures

Its a good idea to keep the coastguard informed of any diving activities, particularly, where you are, where you are going, the size and type of vessel, your call name, how many are on board and when you expect to return, this is because of two main reasons:

1. If you get lost or are involved in an incident the coastguard has all your details, including home contact numbers if you have registered a CG66. (Vessel information)
2. You may be needed to assist another vessel in distress, dive boats tend to be very fast and well equipped, and can often be at an incident very quickly, but only if:
   • The coastguard knows where you are.
   • you are competent to receive and send urgent radio messages
   • If you have established an efficient diver recall system
   • You are, or have on board, a competent boat handler

Sending and receiving radio messages is very straight forward, but is governed by strict radio protocol which must be observed at all times. Lives could be needlessly lost by someone calling for help on the wrong frequency, or by not sending an accurate message of position and circumstances. By following these guidelines when using the radio, even novices or people unfamiliar with procedures could successfully summon help.

1. Plan your message, jot down these facts:
   • Who you are "Grove Diver 1", "Grove Diver 2" etc.
   • Number on board
   • Your Position Lat and Long if available (on GPS). This is crucial if emergency
   • Brief message e.g., Diving wreck Hermine, expect to be here for two hours. etc
2. Before transmitting any message:
   • Select channel 16 - DO NOT CALL ON ANY OTHER CHANNEL
   • Listen make sure there is no radio traffic especially Mayday Sillonce
   • Have your written information in front of you.
   • Tell everyone to be quiet!
3. Call “Holyhead Coastguard” repeat, “this is Grove Diver 1” Repeat. Then wait
4. When the Coastguard responds, he should direct you to channel 67 (or another channel)
5. Change to that channel and wait until the Coastguard acknowledges your call.

Additional points:

• Always remember to inform the Coastguard when you have completed and are near to (not in) the harbour
• Do not pass messages on channel 16.
• Do not transmit on Dual Watch.
• Remember to switch back to 16 after your message has been acknowledged.

VHF Radio Course

The club runs DTI accredited VHF radio courses from time to time. These courses cover all aspects of VHF radio protocol, including the phonetic alphabet, and how and when to transmit radio messages.all aspects of using the club radios.

New system - GMDSS introduced in 1999.

GMDSS is a series of sub-systems that together allow mariners to communicate with each other and the emergency services. These sub-systems cover short range VHF, medium range MF, long range HF and satellite radio sets. Other areas addressed are EPIRBS plus NAVTEX receivers, which obtain text weather forecasts and navigational warnings which are broadcast twice daily. As most dive boats are only equipped with marine VHF radios, this will be the only option covered in this article.

A GMDSS VHF radio has a unique nine-digit number known as a Maritime Mobile Service Identity (MMSI), programmed into it. Wray Castle Ltd., an agency contracted by the DTI to issue them issues this MMSI, and also to issue ships radio licenses in the U.K. The calling channel will be changed from channel 16 to channel 70. This channel uses Digital Selective Calling (DSC), where other stations can be called using their MMSI, the equipment automatically switches both stations to a designated working channel. Of course, you will have to know the MMSI of the other station: the MMSI of coast stations will be well publicised. If you don't know the MMSI of another vessel, it is possible to put out an "all ships" call on channel 70. Ships in radio range will change to the channel you have identified and listen for your voice message.

In the event of a distress call, a dedicated button is pressed which transmits your MMSI on channel 70. If your GPS receiver is connected to the VHF your position is also transmitted with regular updates. All ships and coast stations within radio range hear distress calls. As this is digital technology the radio range is approximately doubled and the message is transmitted more quickly than with voice calling. After making the initial DSC distress call the Mayday procedures are the same as they are at the moment using channel 16, but without the initial distress message. Once you switch to channel 16 the range of the transmitter is restricted by the old analogue technology.

GMDSS is not compulsory for small craft, but this depends on the goodwill of the Coastguard Agency. From 1st February 1999 it is mandatory for all craft over 300 tons to be equipped with GMDSS technology. However, after this date it is not necessary for the Coastguard Agency to keep a listening watch on VHF channel 16. In the U.K. the Coastguard Agency has agreed to maintain a watch on channel 16 for the foreseeable future. Some other European countries have said they will not maintain a listening watch on channel 16, so if you want to contact the Coastguard in those countries, you will have to use a GMDSS VHF radio; and you will also need GMDSS equipment to call ships.

U.K. based dive boats will still be able to communicate with UK Coastguard Stations and other dive boats without too many problems, but the operational procedures may change. During the GMDSS Conference held in Plymouth in 1997, several recommendations were made:

• Small vessels should keep channel 16 for distress and monitoring.
• Small vessels to use channel 16 for distress purposes only.
• Channel 13 should be the calling channel, once contact is made immediately switch to a working channel.
• Coast stations to continue to monitor channel 16 for distress only, to be continued until 2001 with the option to extend this to 2005.

These recommendations have not yet been adopted, so please do not start using channel 13 as the calling channel.
As divers, we need to know that there are likely to be changes in procedures coming into force in 1999. If the recommendations are adopted, update information will be made available to members, and relevant changes made to the BSAC Marine Radio Operation Skill Development Course.