Frequently Asked Questions

Yes. You can take the output from the AISWatchMate or AISWatchMate RX and send it directly to your computer's serial port. If you have charting or navigation software that accepts AIS data then you can run your computer at those times when you wish and still have the benefits of the AISWatchMate. Both the AISWatchMate and AISWatchMate RX provide NMEA multiplexing which means they will merge both GPS and AIS data into a single output stream.

Yes. If you have a chart plotter that accepts AIS data, you can hook it up directly to the AISWatchMate or AISWatchMate RX.

The AISWatchMate RX has an integrated high performance two channel AIS receiver built into it. When using a AISWatchMate RX there is no need for an external "black box" AIS receiver. However, if you are using a AISWatchMate then an external AIS receiver or transponder is required.

The AISWatchMate is designed to work with class B transponders. Together they create the ideal AIS collision avoidance system. You'll be broadcasting your position to all other vessels in your vicinity as well as being able to see all the AIS targets around your and take active action to avoid collisions. In addition, the AISWatchMate continuously monitors the transponder for any problems, such as a disconnected antenna or lost GPS signal, and reports those problems to you.

Class B transponders broadcast your position but do not provide any type of display for received AIS information. Without a display you are relying entirely on someone else to watch out for you and other vessels may not have a sophisticated warning system like the AISWatchMate. The AISWatchMate works especially well with class B transponders and the combination makes the ultimate AIS collision avoidance system. You'll have the enhanced safety benefits of broadcasting your position along with the advanced warning, filtering, and prioritisation capabilities that are unique to the AISWatchMate.

A splitter allows you to use your current VHF antenna instead of fitting another one. You'll probably get the most range this way because your existing antenna is likely to be mounted up high. If you decide to get a splitter, you must use one designed for AIS. If you have a transponder you must use a splitter designed specifically for use with AIS transponders.

AIS transponders are required on all ships over 300 tons when operating internationally and 500 tons when operating domestically. Passenger ships are required regardless of their destination. This means that nearly every commercial vessel will have one. In addition, many yachts and other vessels voluntarily carry an AIS transponder. Each year more and more vessels are equipped with AIS because of the significant safety benefits.

AIS data is transmitted from vessels at a variety of rates. Class A ships send position updates every 2-10 seconds depending on their speed. Class B sends every 30 seconds. Some information, such as the vessel's name and size, are sent every 3 minutes. The AISWatchMate continuously updates bearing, range, CPA, and TCPA for every vessel whenever a new position is received from the vessel and also whenever your vessel moves. In addition, the AISWatchMate displays the time that has elapsed since each vessel has sent its last update. This is useful to help you determine the currency and accuracy of the data presented.

You can easily connect a 12 volt buzzer or indicator to the external alarm wires. The AISWatchMate can switch any device that draws up to 2 amps without the need for an external relay. The wiring diagrams for the AISWatchMate and AISWatchMate RX show how to connect an external alarm, buzzer or indicator.

Be sure you have a GPS connected either directly to a port on the AISWatchMate or routed through an AIS receiver. If you are using a transponder, make sure the transponder is setup to provide GPS data. You can verify that GPS data is being properly received by the AISWatchMate by using the procedure for examining the incoming data stream.

Make sure you've got the port that the GPS is connected setup properly. Use the device settings menu to verify that "GPS" is selected as the input device. However, if the GPS data is being provided by an AIS receiver or transponder then select "AIS" as the input device.

Ensure the GPS has a valid satellite fix. If it doesn't indicate a valid fix then the AISWatchMate won't use the data it provides. If you have a AISWatchMate RX use the GPS Satellite Status page. You can also verify this by examining the GPS screen or by looking at the data stream. When you are looking at the NMEA data stream, locate the $GPRMC sentence and you should see something that looks like this:

$GPRMC,083646.59,A,3650.320,S,17444.970,E,0.0,274.0,180109,19,E,A*00

Look for the "A" in the 3rd field. If it is a "V", or something other than "A", then the GPS doesn't have a valid fix. Check for a loose antenna connection or other wiring problem on the GPS.

Check the setting "Course and heading mode" or "Bearing to target mode". If it is set to magnetic and you are still seeing your heading or target bearings in true, then it's because your GPS is not providing magnetic variation. Marine GPS units usually include this data in their RMC sentence, but embedded GPS modules, such as those used in transponders and other devices, do not provide magnetic variation.

If you have a transponder and you want magnetic headings or bearings then you will need to connect the AISWatchMate to another GPS. You can do this by using the second port on the AISWatchMate and selecting GPS as the input device for that port.

It's sometimes useful to verify that either AIS or GPS data is being properly received by the AISWatchMate. To do this, turn off the AISWatchMate. Then switch it back on by pressing the power button while holding the top button at the same time. At the top of the screen will be "Data Received from Port 1". The raw NMEA data stream will be displayed on the screen. You can pause the display by pressing and holding any button. When you release the button the data display will continue. If you see all dots (".") then it probably means you have the port set to the wrong device type or a wiring problem. Restart the AISWatchMate normally and check the settings for that port.

To exit from the raw data display, press the power button. To view the data stream on port 2, turn the AISWatchMate on by holding the 2nd button from the top while pressing the power button.

Yes you can. If your transponder has a cable with both the computer serial output connector (a 9 pin connector called a DB9) then you can plug it directly into a serial port on your computer or use a USB-to-serial adapter. You can then use the NMEA output from the transponder (for most Class B transponders these are the orange and black wires from the 4-wire stripped & tinned gray cable - check your transponder manual to be sure). Select which port you want to use on the AISWatchMate and connect the orange to the data input for that port. Connect the black wire from the transponder to the signal ground for the same port.

When you hook it up this way, the data from the transponder is sent in parallel to both your computer and your AISWatchMate.