Class B install #2, Digital Yacht bundles

Ben Ellison

Ben Ellison

Panbo editor, publisher & chief bottlewasher from 4/2005 until 8/2018, and now excited to have Ben Stein as very able publisher, webmaster, and editing colleague. Panbo is going to the next level in 2019 and beyond.

6 Responses

  1. JonM says:

    I heard that ICOM will “soon” have an integrated VHF / Class B AIS unit. That seems like a very clean way to solve the shared antenna issue.
    Standard Horizon is supposed to be working on something as well.

  2. Ben Ellison Ben Ellison says:

    Milltech Marine is now selling this same antenna splitter, only under the Comar label. In fact, Milltech has just become Comar’s master distributor in the U.S. and has already added a bunch of AIS receivers to its line, and I imagine Comar’s various transponders will be added once they get FCC certification.
    Doug Miller also reports that the ACR Nauticast B’s that he’s already selling are going out the door “like hotcakes.” Cool!

  3. Sandy says:

    Naysayers still abound at SSCA, assuring each other that some AIS A units (per recent CG release) can’t see AIS B units or can turn them off at will. I recall some knowlegeable source here stating that an AIS B flag with MMSI and data will appear on older un-uped units, but I want to know 1> how big a problem is this, and 2> can or do Captains turn off AIS-B markers?

  4. Ben Ellison Ben Ellison says:

    Thanks for your efforts over there, Sandy, but some folks just plain enjoy naysaying.
    I don’t know how many AIS transponders and/or plotters are currently out there that can not interpret the Class B static data message, but the issue is fairly common. Those transponder displays and plotters do see a Class B target–i.e. the dynamic data–but not the vessel name, type, call sign, and size.
    I think that’s what the USCG warning is mainly about, though there is a mention of older Class A displays that can not even see Class B dynamic data. I’ve never heard of that, and presume it’s quite rare.
    The business of filtering out Class B targets is a mystery. While it seems quite possible to do in software, I don’t know of any AIS transponder or plotter that gives the viewer that choice. And I just checked the manual for the Furuno FA150 Class A transponder (no mention of Class B filtering).
    So while naysayers persistently talk about filtering out Class B targets, I’ve never heard that it can be done, let alone is being done.

  5. del says:

    The Class B position report (msg18) IS listed in the original performance test standard for Class A units (IEC 61993-2 edition 1), therefore (in theory at least) ALL approved Class A units are capable of receiving a Class B position report (msg 18).
    Like you, I am not aware of any display units that allow the user to filter out Class B reports.

  6. bcl says:

    There was a problem with one manufacturer’s AIS not receiving CSTDMA (Class B) transmissions because of a software bug. This was 2-3 years ago when CSTDMA was invented and as far as I know that was corrected by the manufacturer. And no, I don’t remember which one it was.

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