|Using your VHF|
Cocking up your radio protocol is hideously embarrassing and potentially dangerous. Colin Jones shows you how to get it right...
Global Maritime Distress and Safety System (GMDSS) is an inter-nation co-ordination scheme, designed to use the same equipment and Search And Rescue techniques, with a single shore station co-ordinating all actions, but having access to other countries' facilities. These shore-based Rescue Coordination Centres receive distress calls automatically generated by the vessel in distress (the red button on your radio) and contain enough data to allow the RCC to request aid from other vessels in the area, or to launch lifeboats and helicopters.
The systems communications are satellite controlled. Digital Selective Calling (DSC) works much like the telephone system. If you know the target vessel's Marine Mobile Service Identity (MMSI) and it is programmed in your VHF memory, a single button push will alert your correspondent that you are calling. An added benefit is that the DSC call can also carry such other data as your identity, position, the nature of the call and the channel you wish to use for communication. All this takes place on CH 70, which is reserved for DSC and must NEVER be used for any other purpose.
There are a number of other channels to be avoided. Channel 16 is the international calling and distress frequency but you often find people forgetting this and using it for a chat. Make contact, nominate an alternative and get off it - fast. Channels 11-12-14 are exclusively reserved for harbour authorities and CH 09 is used by harbour pilots. Near naval bases, CH 13 is used by their shore control, who get very shirty if you stray onto it. CH 10 is sometimes used by pollution control but, by requesting it from the local Coastguard, it can be 'borrowed' on specific dates for race control. The two channels on either side of 16 (15-17) are labelled as 'guards' to prevent badly tuned radios causing cross-channel interference but, nowadays, are used on very low power, to communicate from one end of a super tanker to the other.
Marinas have their own frequency (CH 80) and 157.85 MHz or CH 37 can be used by UK yacht clubs. In spite of club smart arses calling the Coastguard direct on CH 67 to show off how good they are, calls to HM Coastguard should always be done on CH 16, even though they will normally transfer you to CH 67. This is because that frequency is also their reserve working channel so, if they are running two emergencies simultaneously, you will not interfere (by calling direct on 67) and risk blocking out a very important message from somebody in trouble. There are many seemingly unused channels, especially since the frequency-greedy radio telephone service has disappeared and many of us have our 'private' slots where we think that we will not be monitored. It does, however, pay to be prudent because there are hundreds of short wave hobbyists (who only listen) and their sophisticated scanners will not miss you.
As a rule of thumb, you would do best to stick to the channels reserved for inter-ship traffic. They are 01-08-72-77. There are also a number of channels reserved for 'private' use, but these need modifications to your radio and can be expensive, so they are usually only permitted to such corporate bodies as ferry companies or the military. There is always some confusion about 'private frequencies' and whether it is illegal to listen to them. The simplistic answer is no, largely because nobody can really know that you are doing it, but it is almost a hanging offence to 'use' any info you overhear. I have been unable to locate any case precedent on this, apart from a legal opinion that if you were to discuss what you overheard, that would constitute 'use' and qualify for prosecution.
People are always interesting and the invisible users of VHF are no different. You can tell a lot about a person just by how he uses his radio. Good (and more anonymous) practice is worth acquiring. Most of us pick up the mike and call before we have listened. There may not be anybody immediately apparent because one of the two on-air stations might be beyond your range, but his correspondent might be close and you would swamp his reception. You should wait 30 seconds even before politely asking "Is this frequency in use?" The worst VHF people are the 'gabblers'. They hold the microphone too close to their mouth, which creates hissing feedback, speak too quickly and give far too much information.
Radio-speak really does need each word to be carefully separated from others and clearly enunciated to give all possible help to the guy who is trying to decipher it from a small loud speaker, competing with the electrical interference from several sources, the screaming of an outboard engine and even the barking noise when a planing boat is skipping from wave to wave. Before you speak, compose what you want to say and think of the person struggling at the other end. Here, let me confess that I have frequently been teased because I prefer radio formality to politeness. It makes you sound very military but it cuts out all ambiguity. I much prefer "Affirmative" or "Roger" to "That's OK, Old Boy. I agree entirely. Let's do just that". I also like "negative" and the unambiguous certainty of somebody who says "Out" which is the proper pro-word to signify that you do not expect a reply to your present transmission. In some ways, I prefer the French protocols "á vous, which means "back to you: your turn to speak" and "terminé", which means "ended".
I'm out of here. I also love talking to people like pilots and tug boat skippers, most of whom, (in seamanship terms) are much more senior than me but who will often courteously say "Good morning, Sir, I am fine on your starboard bow. Can we pass green to green?"