Marine vhf radio discussed

The most popular method of communicating with other boats is via very high frequency boat VHF radio.

Equipment is relatively simple, and can therefore be compact and low cost.

To ensure that maritime users do not cause interference for other radio users, a part of the radio spectrum has been allocated specifically to this group and to make operation as simple as possible frequencies have been put into numbered channels.

For example, Channel 16 (usually abbreviated Ch16) actually refers to a frequency of 156.800MHz, although you rarely need to know that.

Because radio does not recognise geographic or political boundaries, and to ensure that boats travelling on international voyages can always communicate, the VHF marine band is the same all around the world.

There are 55 international marine channels, a similar number of private channels (allocated on a local basis to commercial organisations) and some other unique national channels.

The USA and Canada employ a slightly different application of marine channels, using the same frequency but allocating more simplex rather than duplex channels.

National channels include WX (weather) channels in the US, fishing channels in Norway and the marina channels M and M2 in the UK. To make sure that your radio is fitted with the correct local channels, be sure to purchase type-approved equipment in the country of intended use.

What is the range of a yacht vhf radio?

A popular question, with the hardest answer.

Radio travels as waves, similar to light. Like light it can be reflected, reduced or even stopped by other objects.

A popular response to the range question is ‘if you can see it you can talk to it’ (known as line-of-sight) and this is generally a good guide.

Remember however that the radio signal comes from the radio aerial (not the radio itself) and therefore using a higher antenna allows the radio to ‘see’ further.

The same rules apply for receiving a signal, although of course base station aerials are mounted on very high masts and have much higher power, which is another influencing factor.

A stronger, more powerful light can be seen further and more clearly and the same applies to radio. Power is measured in Watts (abbreviated ‘W’)and the higher the power the further the range, but it’s not quite that simple. Even a very low power can give some range. Power can be used to improve the quality of signal and to overcome some obstacles.

Remember though, more power out means more power in, so shorter battery life for handheld vhf radios or non-recharging batteries. Always start with the lowest power setting and work up.

All fixed sets have at least two power settings, 1W and 25W. Handheld vhf radios have various power levels, Icom’s being typically 2.5W to 5W as standard, with 6W from an optional battery.

Because VHF travels in straight lines, like light, as you travel away from land the curvature of the Earth prevents the signal from reaching you. This happens between 35-50 miles offshore. If you still need to communicate beyond those distances you need to look for some other way of doing it.

Handheld VHF 

Marine radio handhelds are among the most reliable and waterproof in the market.

Mounted VHF radios

For vessels with battery power, a fixed radio is a good choice.

SSB (Long Range) radios

HF/SSB radio plays an important part in maritime communications; it provides mariners with a viable and effective form of communication over long distances.

Commercial radios

From base stations for co-ordinating marine traffic offshore to repeaters for extending operating range and full communications systems for super yachts.