Tech: Installing an Automatic Identification System (AIS) show vessels transmitting AIS signals.
It's not everyday you purchase a product that comes with this dire warning.

These commodities may not be used in the design, development, production of nuclear, chemical or biological weapons or missiles.
I'm surprised Somalia is not on the list too, as undoubtedly pirates would find it easier to track vessels equipped with AIS, such as those captained by Captain Phillips (2013 movie).

AIS, which stands for Automatic Identification System, is an automatic tracking system used on vessels and land stations for identifying and locating vessels. An AIS receiver detects the locations of vessels whereas a transceiver additionally transmits the location of the given vessel. In order words, pirates only require a receiver, since they have no desire to broadcast their location. On the other hand, if you want to be detected by other vessels, then a transceiver is what you need.

Being easily detectable, especially by the freighters that ply Gulf St Vincent and Backstairs Passage, is exactly what I want. In keeping with (mostly) Raymarine electronic equipment on Arriba, I chose the Raymarine AIS650 transceiver. Somewhat annoyingly, the AIS650 comes with its own GPS receiver and GPS antenna, which means Arriba now has three fixed-installation GPS receivers (not to mention handheld units).

Anyway, the transceiver transmits and receives AIS signals, which are data signals in the VHF frequency range, i.e., 30 MHz to 300 MHz, which are converted into NMEA messages. The NMEA messages go out onto the SeaTalkNG (NMEA2000) bus, and are interpreted and displayed by an electronic chart plotter, a.k.a. multi-function display (MFD). You have a choice of (1) installing a dedicated VHF antenna for your AIS or (2) installing a VHF splitter in order to use your existing antenna, the latter being the far more sensible choice. The splitter is a so-called active splitter, meaning that it is smart enough to give priority to VHF radio voice and DSC traffic, over AIS traffic. In the loss of power, it falls back to being a straight-through wire so your VHF radio still works.

Note: Before you can configure your AIS, you will need a Maritime Mobile Service Identity (MMSI), which is a unique nine-digit code identifying your vessel that is obtained from your country’s Rescue Coordination Center (RCC). It is the same MMSI used for Digital Selective Calling (DSC). In the US, your MMSI must be pre-programmed by your retailer; you cannot do it yourself.

Here's the step-by-step AIS installation in photos:

Arriba's nav station (above) and autopilot (below). The VHF radio is right below the TV.
The new AIS equipment will be installed below, above the autopilot (grey box).
Wooden board glued to fiberglass will providing backing for new equipment.
(The fiberglass is not thick here and drilling into wood is easier.)
New hole for VHF radio connector.
VHF splitter installed and working (green status light).
Connections (from left to right), power, VHF radio, AIS (not yet connected) and VHF antenna.
2nd SeaTalkNG switch installed.
AIS unit installed, but not yet configured (red status light).
Connections (from left to right), power, SeatalkNG, GPS (white) and VHF splitter.
With the hardware installed, all that remains is to configure the AIS using the supplied software.  The first thing to do is to install the USB drivers for the AIS650.

Raymarine uses ProAIS for the AIS configuration. First, install the USB drivers for the AIS unit. 
Next, install ProAIS software.
ProAIS configuration page. Here you install the vessels static configuration details,
most importantly the MMSI for the vessel.
Scary warning. Make sure you configure the correct MMSI, since you only get once chance!
ProAIS GNSS page shows satellite signal levels.
ProAIS diagnostics page; all is good!
ProAIS page showing other vessels nearby.

Final installation, including some Maretron devices previously located elsewhere.
I have left space above to store an emergency VHF antenna.
That's it! All that remains now is to find a permanent home for the AIS GPS antenna.

Go to to see vessels anywhere in the world (top photo).


PS The installation of the GPS antenna is documented in photos here.


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