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Free VHF/GMDSS On-Line Course

It is not every day you find something free that is worth having (apart from this site of course). As far as I can make out, the Leonardo da Vinci Project to provide an free, on-line radio course has no catches – it genuinely is a free e-learning course. It closely follows the RYA course prospectus, although the area maps cover the Mediterranean rather than UK waters. All you have to do is register, log in with the password they send you, and follow the course. There is even a radio simulator. Here is the link:

VHF and GMDSS Short Range Certificate

If, like me, you took your VHF Operators course and exam many years ago, you may not be aware that you need an upgrade to the GMDSS Short Range Certificate. This involves some tuition on the use of the DSC features that are now standard on all new fixed radio sets, and re-sitting the RYA exam. Although there appears to be little policing of this in the UK, apparently our foreign friends are much more keen on imposing penalties on folk who are operating their radios without the correct certificates.

You can take the full GMDSS Short Range Certificate course in a single day followed by the certificate, or you can take the upgrade course which involves sitting in on the afternoon session of the full course. I can fully recommend the course run by Boatability in Portsmouth. I took the full course as a refresher and I am glad I did – there have been quite a few changes in the last 15 years.

VHF Range

Have you ever wondered how far a VHF signal will reach? It all depends on the height of the aerials, because VHF signals travel in a straight line. Due to the curvature of the Earth’s surface, vessels with low aerials will have a shorter effective radio range than a yacht with an aerial mounted on top of the mast. This explains why you can often hear Portland Coastguard from off the Isle of Wight, but you can’t year a small boat a few miles away. The Coastguard Shore Stations have very tall masts to give maximum radio range. The following diagram, used at the RYA VHF course, shows the approximate range from a shore station to different types of vessel.

VHF range at sea

The Perils of Duplex VHF Channels

The VHF frequencies available to anglers are allocated for different purposes. Some are single frequency, where the sender and receiver takes turns to transmit, and some are dual frequency (duplex) used for ship to shore. The most common duplex channel that small vessels use regularly is Channel 80, which is monitored by many marinas.

A vessel can call a marina on Channel 80, and the marina can reply. However, a second vessel cannot hear the first vessel because its set will not be tuned to receive the transmitting message from the fist vessel. This means it is very easy to accidentally interrupt a conversation between a vessel and a marina, simply because the vessel cannot be heard. This is explained with the diagram below. In crowded areas where there are several adjacent marinas such as in the Hamble, it is better to call the marina on your mobile phone.

duplex VHF problem

Lifetime Radio Licence

The good news is that we no longer have to pay for a VHF Radio Licence every year, a lifetime licence is issued free of charge. If your details are already registered with Ofcom from a previous licence, they will send you a new licence in the post. In the letter are full instructions on how to make changes to your licence on-line. For new licences or to register on-line to change existing licences, follow this link:

You can also check a vessel’s call sign and MMSI number on this world-wide database. “Rebel Runner” is there, I have looked…Follow this link: ITU Particulars of Ship Stations