VHF radio guide

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VHF radio guide

A comprehensive guide to marine VHF radio for leisure boaters; what is a VHF and what to look for when buying one.

August 29, 2017

While a marine VHF (Very High Frequency) radio is arguably the least exciting gadget on board your boat, it’s also one of the most vital. It is designed to enable clear and reliable communications at sea, both from vessel to vessel and from ship-to-shore. It is of course used for run-of-the-mill applications, such as contacting a marina to organise a berth or necessary correspondence with other vessels in your flotilla, but the most important asset of any marine VHF is its ability to raise the alarm quickly, easily and effectively – and that’s something a mobile phone really cannot match…

For a start, while a mobile phone can only contact a specific number, your emergency radio transmission can be heard by everyone, from shore-based services to vessels within range of rescue. More to the point, once a rescue is underway, a marine VHF radio enables lifeboats and helicopters to zero in on your signal much more quickly than a mobile phone can. And that’s to say nothing of the fact that mobile phones are fragile, fiddly and prone to very scanty network coverage when away from the shore.

Plainly then, if you put out to sea, whether on a kayak or a superyacht, you need a marine VHF radio. As you might expect there are plenty to choose from, but they all operate according to the same basic principles. Each unit comes with a transmitter and a receiver that operate on specific frequencies (or channels) in a region of the radio spectrum specifically set aside for that purpose. In addition to various private commercial and unique national channels, there are 55 international marine channels that remain consistent throughout the world. Channel 16 (156.800MHz) is the international calling and distress channel but the development of DSC capability now offers us an easier and more reliable means of raising the alarm.

What is DSC and why do you need it?

Digital Selective Calling (DSC) enables you to contact a similarly equipped craft directly or to send a distress signal at the press of a button. When you register your DSC radio with OFCOM you receive an MMSI (Maritime Mobile Service Identity) number, which means that when your radio sends and receives information digitally on Channel 70, it is embedded with your identity and (if linked to your GPS unit) your location. It is a much more effective means of getting emergency assistance than a simple voice request on CH 16 – and for that reason alone, it’s a device worth pushing your budget for.

The fact that every DSC radio is essentially equipped with its own ‘telephone number’ means it’s also a great way to make specific calls to a known vessel. You simply enter the vessel’s MMSI into your radio, specify your favoured channel for correspondence and your radio then broadcasts the number on Channel 70. The radio of the intended recipient recognises its MMSI, alerts the Skipper and when that person accepts your call, both radios select the specified channel and you are free to conduct your conversation. On AIS-equipped radios like Standard Horizon’s high-spec GX2200E, the process of contacting a target vessel can be even easier – requiring little more than a touch on the relevant target on your display.

VHF licensing and training

If you have a fixed VHF radio on your boat, you need to license it. When you make your application to OFCOM, you are required to share basic information about your vessel and your safety equipment – which means that when you get your licence with your unique call sign (made up of a mixture of numbers and letters), the Coastguard can quickly match your boat to your details in the event of an emergency distress call. If you have a handheld radio, that must also be licensed. It can be done online and it only needs doing once, but such is the importance of ensuring the efficiency of marine VHF and its operation that failure to do so can incur a large fine or even a prison sentence.

For the same reasons, the user of a marine VHF radio (as well as the radio itself) requires at the very least a qualification known as the Marine Radio Short Range Certificate. It only takes a day and is designed to cover basic radio operation (such as channel designations, the phonetic alphabet, emergency transmissions and correct procedure. It also covers the essentials of the DSC system and while this stuff might sound pedantic, it is designed to ensure that you do not clog up the airwaves with idle chitchat, operate on the wrong channels or get in the way of others who may have genuine need of assistance. As you might imagine, UK policing of such qualifications is not exactly watertight, but that doesn’t absolve you from abiding by the rules. The RYA holds a list of course dates and venues and the course costs from around £100.

Handheld VHF radios

Modern handheld VHF radios are extraordinarily sophisticated devices. Their compact size makes them easily portable and their independent battery banks make them a very reliable backup for a boat’s fixed unit. On small craft with short-range communication requirements, like compact day boats, personal watercraft and sea kayaks, they can also operate very effectively as standalone devices. In terms of basic features, a really good portable VHF radio should be waterproof and buoyant, with large buttons, an easily legible screen, idiot-proof shortcuts and a user-friendly interface. It should also feature an adjustable output to help manage battery life, plus a generous array of channel presets (with dual or even triple scan facility), a lengthy warranty of three years or more and potential transmit power of around 5W. If you look toward the upper end of the market, you can also get DSC, as well as weather alerts and even Bluetooth capability. But with prices from less than £60 to more than £400, your choice is likely to be as much about your budget as your wish list.

Read our separate feature on the best handheld VHFs.

Fixed VHF radios

With its large, elevated, external aerial, its permanent power source and its generous physical proportions, a fixed VHF is always likely to give you better performance as a marine communication device than a handheld unit. You can routinely expect transmit power of around 25W – and while, in theory, that will help extend your range beyond that of a handheld, the nature of the installation is even more important. Mount it as high as possible on a vertical antenna and you essentially enable it to ‘see’ beyond the immediate curve of the horizon. The higher the better – and that goes for the receiving antennae as well.

Even then of course, VHF is about relatively short-range communications, so if you’re heading offshore, satellite comms are a very good idea. But there are plenty of big name players in the fixed VHF market, with the likes of Raymarine, Garmin and Lowrance all offering worthy products – and with some of the physical constraints of the handheld unit removed, prices for a fixed unit are broadly similar, tending to range from £120 for an entry-level leisure unit to around £650 for a top-of-the-line device.

Fixed VHF radio best buys

Cobra F77 (£174.99)

Despite its modest price, the F77 comes with built-in GPS receiver for instant location data, plus a ‘Rewind-Say-Again’ feature, which automatically records the last 20 seconds with a digital voice recorder so you can replay a missed VHF call. It also comes with a PA output for connection to an external speaker, as well access to all NOAA Weather Channels. With IPX8 waterproofing, it’s also far more robustly constructed than the price point suggests.

Icom IC-M423G (£299.99)

The G model is basically the same as Icom’s outstanding M423, but with an integrated GPS receiver to enable your position to be transmitted via a DSC call. It also has a white backlit LCD to improve visibility, along with a new microphone with 45mm speaker. In addition to Icom’s classically intuitive rotary selector and keypad, Active Noise Cancelling reduces background noise by up to 90 per cent and (with the optional HM-195G) you can also operate all radio functions, including DSC, remotely.

Standard Horizon GX2200E (£429.99)

This flagship model from Standard Horizon is a fully featured DSC unit with integrated receivers for both GPS and AIS – and with a built in duplexer, it enables VHF and AIS to use just one VHF antenna. An AIS target is displayed on the 1.8-inch LCD screen, enabling you to see the vessel’s MMSI number, call sign, ship name, bearing, distance, SOG and COG. There is also an alarm to warn you if a target vessel strays too close, plus a 30-Watt loud hailer with pre-programmed fog signals, a ‘ClearVoice’ noise cancelling speaker microphone and a three-year warranty.





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