EARS | Marine Band Radio


Our new range of plotters offers additional safety and information for small boat owners.


These devices use the AIS (Automatic Identification System) to produce on a display the relative positions of other vessels in the vicinity of your exact location. Larger vessels over 300 Gross tonnes are required to carry AIS transponders to broadcast their position, identification, type, course, speed and navigational status to suitably equiped shore stations, other ships and even aircraft. These larger ships use Class AIS, which broadcast their position and other data every few seconds and are usually interconnected with the ship's other systems and have dual receivers to operate effectively.

The other cat5egory of AIS is more suitable for smaller vessels and leisure craft. They are simplified and can combine charts and maps with the GPS display, and incoming AIS data to produce a pictorial view of the local area. Normally their data is sent in packets separated by 30 seconds or so, but this is perfectly acceptable for smaller and more agile vessels, even in crowded waterways. The main difference between all the available units is the size of the screen and the extra features they have - making appropriate selection something that is mainly down to the features, and what advantage they have for the user. There are small differences in how the data is presented between the commercial Class AIS and the small vessel system. The commercial sets will include details about the vessel, it's destination and type so a tanker is clearly different to a cruise liner. With class B, the normal requirements to be included in the broadcast data will be MMSI number, callsign, boat name and it's type. Some can also give details of length and beam. These need to be programmed in. Like all devices that transmit, an AIS transponder on your boat requires adding to your OFCOM radio licence. They also offer fishermen the facility to tag nets with an AIS buoy and it's location will appear on the display. As with car SatNavs, the mapping can be selected from a number of paid sources and some free sources, depending on the level of detail you require. They normally are supplied with a GPS antenna that needs to be fitted but also need a separate VHF antenna, or splitter network to enable reception and transmission of data. This has an impact on range, so various types can be connected. Keep in mind that commercial vessel systems involve high power and taller antenna locations so their range is greater -  for a small vessel Class B system, 7 to 10NM would be typical. Collision avoidance is one common requirement for boat operators decision to purchase and install AIS, but leisure users who often go to see in small groups find knowing the realtive positions of the other vessels in a group very useful.



Size and features

The two AIS transmponders above are broadly similar in features but one has a 4.3" colour display and the other has a larger 7" display. Click on the images for more information.


When you purchase an AIS transponder from us we are happy to do your initial programming for you.

Need Support?

If you think radios could help you - call us for advice - it's free!

01502 568021     01502 218989

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East Anglian Radio Services

40 Bridge Road

Oulton Broad


NR32 3LR

01502568021 - 07885039092



East Anglian Radio Services.


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-- Waterproof hand held with GPS

-- Simple, waterproof hi power hand held

-- vehicle VHF and UHF radios

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Community repeater and radio hire available

Short and long term radio hire

Marine, Commercial and Amateur  equipment available

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Tel: 01502 572136

40 Bridge Rd, Oulton Broad  NR32 3LR


Monday-Friday: 9am to 6pm

Saturday: 10am to 1pm

Sunday: Closed

Out of hours by arrangement




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