It is more and more common to see an AIS receiver, Automatic Identification System (*), receiver above yacht's chart tables. Although only merchant vessels of over 300 tons and passenger ships are required to fit onboard an AIS Class A transponder, small commercial vessels are increasingly fitted with cheaper standard AIS Class B transponders.
Receivers
Found on the yachting market AIS receivers at reasonable prices, as those of company Comar System, Digital Yacht, or even Nasa Marine.
You can also choose to install a transponder (transmitter/receiver) class B, like the Nauticast-B from ACR.
Implementation
To operate an AIS receiver with GPSNavX or MacENC on your Mac, you must follow the following steps :
- Install the FTDI driver used with the majority of AIS receivers. (latest version to download on the Embedded hardware page of my website).
- Connect the AIS to a USB port on the Mac and start it.
- Launch MacENC or GPSNavX.
- Open the window using the “AIS/RADAR” menu > Connect ". In the Settings drawer, select port USBSerial-XXXX, Speed 38400. Uncheck “Use GPS port” and “Use Instrument port”.
If AIS targets are available (data received by the receiver) you will see them in the list of the AIS window and you will be able to see the received NMEA data scrolling in the “Monitor” drawer after clicking the “Launch” button.
Warning : Most receivers do not transmit AIS NMEA data if they don't receive AIS information themselves. The red icon is displayed otherwise.
Advanced functions
GPSNavX and MacENC both support the AIS receivers and transponders.
MacENC also offers the possibility of using an AIS transponder to position yourself without the need for a connected GPS receiver.. Indeed, the transponder having its own GPS positioning system, just select, in the Settings of the “GPS” window, the serial port to which the AIS transponder is connected in the Settings drawer of the “AIS/RADAR” window so that the vessel's position is that of your own transponder. If, however, a GPS is also connected to MacENC, it is then the position from the GPS which will be taken into account.
Caution
The anti-collision safety provided by AIS remains relative and insufficient. Many vessels are not equipped with AIS transponders, and some boats do not start them, like fishermen who don't want others to know where they fish, or Navy ships that do not want everyone to know where they are !
So stay careful and keep visual awareness as the main means of safety..
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(*) See Glossary
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