General FAQ's


Please review our general and product specific FAQ’s before contacting us. This will ensure you obtain the quickest solution to your support inquiry. If you don’t find an answer then please contact us directly at [email protected] providing as much detail as possible, or complete the form at the bottom of this page.


    No, unfortunately that functionality is not supported by any AIS transceiver. Any photos displayed on AIS websites such as MarineTraffic or VesselFinder will have been uploaded manually by the vessel owner.

  • How do I Choose the Right Antenna for an AIS Device?

    One of the most essential parts of an effective AIS system is a well-suited, well installed and fully functional VHF antenna, so it’s no surprise that we’re often asked for advice about how to ensure that this part of the system is setup properly. To try and simplify things, we’d advise that when selecting an appropriate antenna or considering using an existing antenna, you consider the following points:

    1. If an antenna works well with a VHF/DSC voice radio, this is no guarantee that it will also work well with an AIS transceiver. This is because Class B AIS only operates at 2W output, whereas a VHF DSC voice radio operates at 25W output and so will still radiate a signal of some type. AIS Class B devices like the B100 do not have the power to “push through” and may not work on such an antenna (even if a VHF Voice radio can use the same antenna).
    2. Use of narrow band AIS ‘tuned’ antennas are not recommended as they are optimised at the standard AIS1 and AIS2 frequencies and may not give optimum performance when regional channel settings are used.
    3. AIS optimised ‘broadband’ antennas are suitable for use; these antennas typically have a wider bandwidth to give improved performance at the top end of the VHF band where AIS usually operates.
    4. Siting of an antenna is crucial as even a well suited antenna may not radiate a good signal if installed in a poor location. Put simply, keep the antenna upright, clear of anything that could touch it (rigging/other antennas etc), keep a reasonable distance from any other devices/antenna arrays like Radar/HF/VHF radio that may be operating at high power and also keep clear of any other metallic obstructions.

    If you’re still unsure of which antenna is right for you, please refer to the list below for some advice:

    Typical VHF antenna specification:

    • Band: Marine VHF band (nominally 156MHz to 162MHz)
    • Impedance: 50 Ohms
    • Gain: 3dBi
    • VSWR: <1.5:1 at resonant frequency
    • Max power: Typically >25W
    • Polarisation: Vertical
    • Bandwidth: Typically 6MHz
    • Cable: RG58 or better. Note the IMO recommend RG214 or better for SOLAS installations
    • Connector: PL-259 (sometimes called ‘UHF’)

    Establishing a connection

    To connect to proAIS2 you will need to select the relevant device (usually ‘AIS Class B Transceiver’ for Windows and ‘AIS Virtual COM port’ for macOS) from the drop down menu at the top of the screen before pressing the ‘Connect’ button. If there is no suitable device to select, please ensure the USB cable is securely connected and that the appropriate LEDs are illuminated to indicate it has initialised. If you are still unable to connect to proAIS2 after verifying the connection please contact [email protected] for assistance.

    ‘Configuration’ tab

    Vessel Details:

    You will need to populate these fields using the details from your ship license.

    The MMSI number will be the same as the one issued for your VHF radio. If you have not been issued with an MMSI number you will need to contact your local authority. Please contact [email protected] if your MMSI number has already been configured and you need to change it. The remaining vessel data can be edited using proAIS2 once configured. Configuration of the call sign is not required if you do not have one.

    Ship’s Dimensions and GNSS Antenna location:

    Enter the position of your GPS antenna (in metres) in reference to the four dimensions of your boat. If your unit is using its internal GPS antenna you will need to enter the position of your unit.

    Configure Baud Rates:

    This setting controls the speed at which data is output from the NMEA 0183 port(s). You will need to ensure it matches the baud rate of the connected equipment (for example, a chartplotter or VHF radio). Typically, chartplotters require 38,400 baud and VHF radios require 4,800 baud. AIS data should not be configured for output at baud rates lower than 38,400 – this is because messages may be dropped when travelling through areas of high traffic where there is a lot of data to process.

    Output GNSS Sentences:

    Tick the boxes as required to output the GPS sentences over the NMEA 0183 port(s). This will usually be defined by the external equipment you’re connecting to, but if unknown RMC is typically required to provide position and SOG/COG. If you require GPS data (PGNs) to be output over the NMEA 2000 port you will need to tick the RMC box.

    GNSS configuration:

    This setting controls the combinations of satellite constellations which are used to get a position fix. It is not supported by the B100, B300, or B330 as they use GPS only.

    Long range broadcast:

    This setting enables/disables the transmission of Message 27, used for long range detection. It’s transmitted on a different channel (frequency) and typically received by satellites. This proAIS2 feature is supported by Class B SO products only.


    Please note that any applied configuration will need to be saved by pressing the ‘Write Configuration’ button.


    ‘GNSS Status’ tab

    Use this tab to check the performance of your GPS antenna. This is particularly useful if you’re unsure where you need to mount your unit if it uses an internal GPS antenna. A good GPS fix is 30-40dBHz, although this may be difficult to achieve if your unit is using an internal GPS antenna and there’s an obstruction interfering with the signal.


    ‘Other Vessels’ tab

    This tab shows the vessels in range. The vessels can be sorted by selecting the appropriate parameter at the top of the field.


    ‘Diagnostics’ tab


    If your unit is fully configured and installed correctly every parameter should have a green tick against it.

    Internal Data:

    This field displays software versions, serial numbers, and operational/performance data. You may be requested for this information if you contact em-trak customer support for assistance.

    ‘VSWR’ is Voltage Standing Wave Ratio, and is an indicator of VHF antenna performance. A good VSWR is 3:1 or less, and can be affected by factors such as length or quality of cable and type of VHF antenna connected. If it exceeds the threshold a red cross will appear against AIS Antenna in the checklist field.

    ‘Power supply voltage’ reports the voltage received at the unit. There may be a small drop in voltage between the battery / power source and the unit, depending on the length of cable. External power (12-24V) is required for the unit to receive and transmit.


    Reflects the LED indicator status on your unit. Select the ‘Silent Mode’ button to enable / disable silent mode, where the blue LED will illuminate if enabled.


    Displays the number of messages that have been received and transmitted.


    Occasionally messages will be output in this field depending on the operational status of your product.

    Class B/CS products routinely output ‘CP busy’ or ‘TX attempt failed’ messages; these are normal and relate to the way that Carrier Sense operates, where it needs to listen out for a free slot before it can transmit. You may also see a message relating to RX1 / RX2 and DSC; this is also normal and indicates when one of the receivers is monitoring the DSC channel on a regular, time-shared basis.


    This field displays all active alarms. The alarm will be indicated with a corresponding red LED, either flashing (high VSWR) or solid (other hardware-related failure). If the conditions change and the alarm is no longer active, it will disappear from the list and the red LED will stop.


    ‘Wi-Fi’ tab

    Use this tab to configure the W-Fi interface on your unit. The configurable parameters will differ between the B330 / B360 products and the newer B200 / B900 Series products; the specific details are covered in the product manuals. This tab is only available on products that support Wi-Fi.

    As with the vessel data configuration, you will need to press the ‘Write Configuration’ button to save any changes.


    ‘Serial Data’ tab

    Raw serial data is output on this tab. It can also be used to log the serial data to a file (which may be requested for diagnostic purposes if you contact em-trak for support), and there’s a field to enter command(s), if you have requested a configuration that isn’t supported directly by proAIS2.


    ‘VDR’ tab

    Your position is automatically logged every time your vessel moves more than 10 meters, and this tab can be used to download that data from a selectable date range. The VDR feature is only supported on Wi-Fi products, and this proAIS2 tab is currently available for the B330 and B360 only.


    If you have a question relating to proAIS2, and it isn’t covered in this article, please contact [email protected]

  • What are AIS Tracking Websites and how do They Work?

    If you are travelling and want the folks back home to see where you are, or even if you just want to get an idea of what vessel traffic is like , prior to leaving home; AIS Tracking Websites have become a very popular and useful hobbyists tool.

    Sites such as and offer a free service where web users can search for vessels that are represented on maps or even old satellite images.

    On occasions, we are asked to explain why a customer’s vessel might not be appearing on these sites as there may be some concern that the unit is not operating correctly.

    If you are concerned that this may be the case with your AIS transceiver then please consider the following:

    • Coverage: Not all AIS websites offer complete coverage, so there is a chance that you may be out of range of a receiving station for that site.
    • Antenna setup: If you are being seen by other vessels around you, but not by the AIS website, then the issue could be associated with your choice/installation of VHF antenna. If in doubt, refer to the user manual for advice or contact us for help.
    • Unit configuration: Make sure that your AIS transceiver is correctly setup with its complete vessel details and that it is connected to a GPS antenna (as per the user instructions).
  • What is a Transceiver?

    A transceiver is a device that transmits and receives information. Class A and Class B devices are popular examples of AIS transceivers.

  • What is AIS?

    AIS is a relatively simple concept as it uses VHF and GPS to transmit data to other ships significantly increasing the safety of you, your crew or your family.

    AIS, or Automatic Identification System, is an ideal way to see and be seen in busy ports, waterways and out at sea. It is a simple concept, fusing dynamic and static data together to build up a live image of the surrounding marine environment which is then displayed on a chart plotter or on board display.

    AIS works via a combination of GPS, VHF radio, and an AIS transponder. The transponder broadcasts a ship’s information, such as speed and heading (information gathered by GPS), the ship’s name, port of origin, size and draft, and more, over VHF frequencies 161.975 megahertz and 162.025 MHz. This information is updated constantly and can be viewed by any other ship or boat equipped with an AIS unit, as well as on any chart plotter, MFD, computer or smartphone linked to the internet.

    AIS provides many benefits to mariners greatly improving situational awareness and decision making.  With AIS onboard your boat will be a safer boat.

    If you are unable to find the answer to your question please complete the form at the bottom of our contact page and one of our customer representatives will contact you within one (1) working day.

  • What is an MMSI Number?

    An MMSI (Maritime Mobile Service Identifier) is a nine digit number used to identify vessels and coast radio stations. The MMSI is similar to the phone number for the ships radio and can be used to place a radio call to a particular vessel. AIS systems also use MMSI numbers to identify vessels. With the exception of an AIS SART the same MMSI is used for all radio equipment on a vessel, so the AIS should be programmed with the same MMSI as the VHF radio.

  • What is Static and Dynamic Vessel Data?

    Information transmitted by an AIS transceiver is in two categories: static and dynamic data.

    The vessel’s dynamic data which includes location, speed over ground (SOG) and course over ground (COG) is calculated automatically using the internal GNSS receiver.

    Static data is information about the vessel which must be programmed into the AIS transceiver. This includes:

    • Maritime Mobile Service Identity (MMSI)
    • Vessel name
    • Vessel call sign (if available)
    • Vessel type
    • Vessel dimensions
  • What Kinds of AIS Devices are There in Use?

    Class A transceivers: These are designed to be fitted to commercial vessels such as cargo ships and large passenger vessels. Class A transceivers transmit at a higher VHF signal power than class B transceivers and therefore can be received by more distant vessels, and also transmit more frequently. Class A transceivers are mandatory on all vessels over 300 gross tonnes on international voyages and certain types of passenger vessels under the SOLAS mandate.

    Inland AIS stations: Similar to class A transceivers with additional features for use on Inland waterways.

    Class B transceivers: Similar to Class A transceivers in many ways, but are normally lower cost due to the less stringent performance requirements. Class B transceivers transmit at a lower power and at a lower reporting rate than Class A transceivers.

    AIS base stations: AIS base stations are used by Vessel Traffic Systems to monitor and control the transmissions of AIS transceivers.

    Aids to Navigation (AtoN) transceivers: AtoNs are transceivers mounted on buoys or other hazards to shipping which transmit details of their location to the surrounding vessels.

    AIS receivers: AIS receivers receive transmissions from Class A transceivers, Class B transceivers, AtoNs and AIS base stations but do not transmit any information about the vessel on which they are installed.


    CONNECT-AIS allows your smartphone to securely connect wirelessly to your B922, B924, B952 and B954, configure it and automatically monitor its health and performance.

    The Android version of CONNECT-AIS can be downloaded from Google Play –

    The iOS version of CONNECT-AIS can be downloaded from the App Store –

  • Where do I go to find Configuration Software?

    Simply click on the image of the product you are installing below.   This will take you into the support page for that product where you find FAQ’s, Manuals & Downloads and also Configuration Software for download.  If you need any assistance please contact us at [email protected]

Please select your specific product for detailed support, trouble shooting and technical information.

Core technology


Core technology continuously developed and proven over many years guarantees you the very best AIS receive and transmit and GPS performance, coupled with the lowest power consumption of any comparable AIS transceiver.



Quality engineered and manufactured with the best components to provide years of continuous, maintenance free operation in even the most extreme environments – impervious and protected against the long-term effects of water, damp, shock, vibration and extreme cold and heat.



Guaranteed connectivity to any chart-plotter and PC/Phone/Tablet/Watch and navigation app. This ensures you are not limited to any display device or navigation application now or in the future and can maximise AIS related functionality such as weather, MOB, anti-collision, anchor safety, vessel tracking and more.  



With features such as FLEXI-FIT bracket, integrated GPS antenna, VHF antenna splitter and unlimited connectivity options such as NMEA2000 & 0183, Bluetooth & Wifi. em-trak AIS transceivers are easy to configure and install on any boat.  



em-trak transceivers are rigorously tested and certified for global regulatory compliance. This includes FCC, USCG, Canada and EU test and certification.


Warranty & support

em-trak transceivers are designed and engineered for a life time of reliable operation in even the most extreme environments. This is supported by our best in class global warranty program with 24/7 customer support