Friday, November 8, 2013


An Automatic Identification System is one of those things that just seems like a good idea.  (Unless you are one of those people who lies awake at night, loaded gun under your pillow, waiting for the Black Helicopter to swoop in and drop a UN Ninja Warrior Team on your butt.)  It would be nice to transmit though I doubt the big boats would (or could) move out of the way even if they got an alarm.  It would be really, really, nice to receive; giving us plenty of warning to get out of the way - even on a dark and stormy night when visibility is measured in parts of a boat length.

So it came to pass the we went to the Annapolis Boat Show with an AIS receiver at the top of our "buy" list.  After stopping at several booths we ended up talking with a knowledgeable sounding young man about the Standard Horizon GX2150 with MATRIX AIS+.  (Sounds really cool, yes?)  This, we were told, was THE unit for cost competitive AIS information and warning; all set to go, plug and play.

That seemed a bit too good to be true.  A VHF, all by itself, would have scant chance of giving even a hazy azimuth (or bearing) to a target, and no chance of giving a range.  So I asked, "The GX2150 has an internal GPS?"  And guess what?  I was assured by this knowledgeable sounding young man that, yes indeedy, a GPS came in the unit.  It seemed a bit odd that the manufacturer would go to the trouble of installing an internal GPS and then not have add on navigation capabilities offered, so I asked the same question again, this time with a bit more emphasis.  And I got the same answer with equal emphasis...plug and play, you'll have a good day.

So I bought it.

Only to discover upon installation that the Standard Horizon GX2150 with MATRIX AIS+ only has that AIS+ if you wire it into a GPS receiver; otherwise it is just a nice looking VHF radio.  Goat roping low life son of a donkey ... had by the marine industry once again.

Fortunately motoring down the ICW in a parade of boats isn't that hazardous, even if the MATRIX AIS+ lies inert and clueless.  But with the engine work gone as far as it can go until parts arrive, and it being a bit warmer inside the boat than out, and with Deb being her normal productive self this afternoon, I felt compelled to be useful as well.  Why not take a look at the AIS?

Two inches from the GX2150 is mounted our old Garmin GPSmap176.  It isn't much use as a chart plotter but it does talk to satellites and knows where it is in a latitude and longitude sort of way, and that is all the VHF needs to know.  Perhaps we could introduce the two to each other and have them make beautiful AIS music together.  A few hours of phone calls, emails, internet searching, manual studying, and head scratching later and it was done.  GPS Brown wire meet VHF Blue wire.  VHF Green wire meet GPS Black wire.

We now have a cute little AIS screen complete with symbols for boats displayed in relation to Kintala, CPA and Time to CPA alarms, a list of the boats on the screen, all kinds of direction and speed data, and even the ability to call them direct.  When first cranked up it beeped to let me know there was a boat right on top of us: BLACK CAT - Dist 0.01NM - BRG 218 deg T - CPA 0.01 NM - SOG 0.0 kts.  Stuck my head out the companionway and, sure enough, BLACK CAT, a very pretty catamaran, is tied directly across the dock from us.

I likes me some AIS.


Unknown said...


I have been following your blog daily and it is providing with inspiration as I put my 1981 Tartan 42 back together. I have learned a lot from your blog and look forward to your daily posts.

I would like to get your e-mail address to be able to contact you directly with questions.



S/V Veranda said...

AIS is like having a third crewman aboard during those overnight watches....