Choosing a radio for both Land and Marine use.
Marine radios for use at sea use VHF (Very High Frequency) channels. This a worldwide standard. It is use is strictly controlled for marine applications only. All transmissions can be geolocated by the MCA and cannot be used on land in the UK except in some very exceptional circumstances. So a Marine radio can only be used on water on some inland rivers and at sea.
With a few exceptions land radios are also tightly controlled. Licenced by OFCOM, but they can be used on both land and at sea (with a few restrictions).
Land radios can use either UHF (Ultra High Frequencies) and VHF frequencies. UHF being most commonly used in urban environments as it penetrates buildings best. VHF is often, but not always chosen for more rural applications.
Land radios are manufactured to be either UHF or VHF versions but not both. So for a single radio to work on both Marine and Land channels it must be of the VHF variety.
Marine radios need a Ships’ Portable Licence, and the operator should ideally complete some formal training..
Land radios nned no formal training but to use any radio channel an OFCOM licence is required. To generalise there are two types of OFCOM land licence;
- A Geographic licence which gives you a private radio channel for your use anywhere within a circle of a few km of a point of your choice. Ideal for Sailing clubs for instance but nor so good for general adventuring.
- A UK Simple Light licence. This gives you three radio channels to use anywhere in the UK but those three channels are shared with anyone else issued with that same licence. And hundreds are issued every year. Thousands of these licences in total.
You are mostly not going to hear those other users for two reasons: They are too far away. There are three channels, so those close enough may be using one of the other two available channels. BUT you will hear other users occasionally so there is a filter built into Land radios to prevent this. It's called CTCSS.
Continuous Tone Controlled Squelch System (CTCSS) is used to keep Land radios silent to other users sharing your channel. It is only used on Land channels, not on Marine VHF channels so all but very high end Marine radios are not CTCSS capable.
- Land radios can be programmed with Marine channels although Land radios don't usually have the convenience of labelled channel 16 buttons and many of them are not waterproof.
- Marine radios are not capable of working on Land channels as they dont have CTCSS with a few high-end exceptions.
- Many marine radios may be able to work on Land channels without using CTCSS but they will pick up plenty of occasional interference.
- A radio that needs to work effectively on both Land and Marine channels will usually be a high-end (industrial) Marine VHF radio.