Radio Magic

In the science fiction world there is a saying that “sufficiently advanced technology will appear as magic to primitive peoples.” As an example I give you AIS.

AIS, automatic identification system, is a mandated system whereby large ships are required to broadcast their location, velocity, and other information periodically over a VHF frequency. VHF is the widely used band for marine communications. AIS information, when acquired by other boats, has undoubtedly saved a few collisions and relived untold anxiety on the part of watch keepers of boats large and small.

Jan and I on yacht White Pepper have wanted to acquire this technology. A dedicated AIS system is complicated and expensive. Some stand alone units are north of $3000.00 and require another antenna or a splitter at least. AIS would only be really needed by the White Pepper on the two nights of the year when we cross and recross the Gulf Stream on the way to and from Florida to the Bahamas. Since 2010 Standard Horizon, also proudly known as Yeasu of Yokohama, Japan, has offered a unit that combines VHF voice communications and AIS. It is the Matrix AIS+ 2150. However, White Pepper, had a perfectly good VHF unit, an older Standard Horizon, the Eclipse model.

When the Eclipse began to act up—cutting out and changing channels—I quickly got on the internet and ordered the Matrix AIS+ for the grand holiday special price of $280 from Defender Marine. Two days later the unit showed up in the mail. I have always used Standard Horizon radios so the switch out was easy. When removing the old Eclipse, I noticed that the VHF antenna cable was loose! Oh, well; at least I had fully functioning back up for the new radio.

Now comes the advanced technology/magic part. The Matrix radio wants learn the GPS data from you and in return will give back the AIS. I have an older Garmin chart plotter, a 545S. It uses the outdated NEMA 0183 format. Fortunately, so does the Matrix. But how to get the two units to talk to one another? Sometimes they want to talk at 4800 baud and sometimes at 38400 baud. An internet search said the solution was easy, but no one bothered to elaborate. The Standard Horizon website had a file on the issue, but it would not load—something about duplicate headers?? A call to Garmin International in Olathe, Kansas yielded some advice that I eventually had to discard. I must have read the three relevant pages in the Standard Horizons Users Manuel 25 times.

For readers that are actually interested in making this connection, here is the magic incantation. The colors are those of the respective wiring harnesses.

Matrix AIS+        Garmin 545              baud

Blue                     Blue                         4800            Port 1 on the Garmin

Green                  Brown                     4800            the common ground

Yellow                Violet                    38400            Port 2 on the Garmin

White                   Grey                      38400            not sure what this does

After about 10 hours of work image my delight and surprise at seeing ships (rather their AIS symbols) on the small but familiar screen of my trusty Garmin—magic!

I do not believe that I have mastered AIS technology, only that I have tricked and charmed it for awhile. Regardless, White Pepper, will be a tad safer when crossing the Gulf Stream this year on the way to the Bahamas.

NB 1-6-13.  White Pepper used the AIS for the first time in combat today.  We were off of Freeport, Bahamas and a cruise ship the Carnival "Sensation" had us  head on 4 miles astearn.  CPA, closest point of approach, was a quarter of a mile.  Every cruiser knows that cruise ships never answer a hail on channel 16, but I called them on DSC directly.  They answered "station calling Sensation."  I asked if they saw me and they seemed puzzled.  They said that I was on the radar.  I asked their intentions.  They said that they were soon to alter course to port and  that I should carry on.  All of this  relieved a great deal of anxiety in the pre-dawn hours. God Bless AIS.