AIS B in the USA, depressing


Honestly, what the hell is wrong with the FCC? Today some one who knows how these things work pointed out to me that the Commission only listed Docket


Amendment of the Commission’s Rules Regarding Maritime Automatic Identification Systems”—on its Items on Circulation list as of November 19.  I’m further told that, though the U.S.C.G. has asked the FCC to expedite this ruling, there’s really no telling when the Commissioners will sign off on it. And you’ll notice that many items on the list date from early 2007 and there are few from 2006! As for Ghassan Khalek’s mid-October “a matter of weeks, not months” and Jose Arroyo’s December prediction, I know not. Depressing.

In the mean time, I’m not sure there’s another nation on earth which either has not approved Class B AIS or doesn’t care. I’m reminded of some amazing recent screen shots sent in by Panbo correspondent Terry Sargent, an AIS early adopter. The one above shows his sloop Valhalla in the Singapore Straits with (see bottom line) freaking 446 AIS targets in range of his NASA receiver! Some of those may well be Class B targets as Singapore has had an interest in the technology for some time. (More Valhalla AIS adventures here.) And finally, not only are we still waiting for Class B AIS in the States, reasons unknown, but there’s a growing chorus of Class B negativity.  Unfounded, I think, but that’s an entry for another day. Depressing.

Ben Ellison

Ben Ellison

Panbo editor, publisher & chief bottlewasher from 4/2005 until 8/2018, and now pleased to have Ben Stein as a very able publisher, webmaster, and editing colleague. Please don't regard him as an "expert"; he's getting quite old and thinks that "fadiddling fumble-putz" is a more accurate description.

19 Responses

  1. august neblig says:

    700 mhz public safety spectrum issues have been all consuming

  2. Brian Lane says:

    It looks to me like Mr. Pot’s ‘FAQ’ isn’t telling the whole story. His ‘Probably Not’ sections contains a few errors and subjective opinions, but not many facts.
    Will commercial ships “see” me with a Class “B” transponder: Probably Not
    • Few commercial ships display AIS targets on their radar

    Ben would know more, but it is my understanding that they use a combination of equipment, so while the targets may not be available on their radar they probably will have a display of some kind.
    • To reduce screen clutter Class “B” targets will be filtered from radar
    Possibly true, but how can you make such a blanket statement?
    • Range is only about 8 NM (2 Watts versus 12.5 Watts for Class “A”)
    True, although this depends in large part of the height of the antennas. In tests I have seen Class-B prototypes work out to 12nm (and these were not optimum transmitters).
    • GPS Position updated every 30 sec. (every 2–10 sec for Class ”A”)
    • Messages only sent if the channel is free from Class “A” Messages
    False. Or misunderstood. Class B messages are sent if the selected slot is free, not the whole channel. It randomly selects 10 slots to try, so the chances of it transmitting are good.
    • Class “A” cannot understand Class “B” Identification Messages
    False. Does he mean Message 24A/B? Older Class A systems may not have ‘understood’ the messages but they can be upgraded, and if they were written properly in the first place they would just pass the data on to the display for interpretation.

  3. Russ says:

    What’s the chance that the FCC would do anything other than approve what is already out there? Would they send the whole industry back to the design table?
    Is the current lack of FCC approval a restriction on sale or usage?
    Would they (do they?) require foreign flagged boats to disable their AIS B transponders in US waters, boarding vessels as they approach the coast to enforce the non-use of units not in compliance? Is that at 3, 12 or 200 miles? That seems like a tall order for a CG who now lives in the DHS and is theoretically focused on terrorists and drug interdiction?
    Sounds like a business opportunity for electronics vendors in Bermuda, the Bahamas, Mexico, etc.

  4. George says:

    I wouldn’t activate one of these devices in US waters. It comes under the jurisdiction of the FCC, and they do care about this stuff a lot. Unlike most unlicensed broadcasts, this one includes your position and possibly your boat name. Talk about making it easy for them! You might find a welcoming party at your dock.
    We had a friend with a legal but malfunctioning cell repeater on their boat. I was quite impressed at how quickly they tracked him down. We can’t feed and house victims of disasters very efficiently, but when it comes to slapping a fine on somebody our government is first rate.

  5. marinate says:

    I hear that some Class B units have Canadian approval, so how does this work near the border?

  6. Rusty says:

    To the best of my knowledge, the ACR AIS-300 is the only class B unit that has been issued a TAC number by Industry Canada. IC knew class B was coming and amended their maritime VHF standard (RSS182) accordingly back in 2003.
    My understanding is that a Canadian vessel would be able to operate a class B in any waters, unless prohibited by the local administration.

  7. Ben Ellison Ben Ellison says:

    Brian, Thanks for an excellent job rebutting Fred Pot’s “FAQ”. I will add that when I tried a Class B back in June, I was seen by almost every ship I queried. I can also testify that even without AIS, I’ve had large ships change course for me when I was offshore in a modest size yacht.
    I’m hoping to get the good gCaptain to ask his ship running readers about their AIS habits, but I’m pretty sure that Fred—though he’s done a great deal to promote AIS—is exaggerating Class B problems.

  8. del says:

    I agree with Brian – and I don’t know why Fred is promulgating this FUD as he was very active in promoting AIS in the early days, and I have even met him on several occasions and he seemed to be a reasonable and knowledgeable chap. Oh well….

  9. george says:

    One of the claims against class B was that the Coast Guard might not be looking at it. That misses an important advantage of Class B. Usually (around here) the Coast Guard is not the first responder; there is almost always some other boat that is a lot closer and can get there even faster than a helicopter.
    Having listened to a lot of such rescues, on of the time consuming parts is for the rescue boat to locate the boat in trouble. A lot of time is spent trying to determine which of two or three radar targets is the boat in trouble. Trying to transmit your GPS location clearly over the radio (and transcribing it correctly if you are the rescue boat) is difficult in times of stress. The automatic system will not transpose digits.
    Class B could really help the nonprofessional rescurer locate you more quickly. I expect that most significant boats will have receive only AIS before long, so they can find you even if you can’t find them.

  10. Russ says:

    I don’t think Fred’s ideas are all FUD. The Furuno professional radar on display at FLIBS had the ability to limit AIS target displays based on various criteria (they call it “sleeping” a target). AIS B was not an explicit criteria, but speed and other factors were. It’s easy to see how something like tonnage could be used to effectively filter out AIS B.

  11. Ben said earlier “Singapore has had an interest in the technology for some time”. Singapore’s system is called HARTS (Harbour Craft Transponder System), which is a slight misnomer with regard to the word ‘transponder’. From 1 Jan 2007 all Singapore registered craft are required to have a HARTS ‘transmitter’ which must be purchased by the owner ($633) and has an annual service fee of $84. They were free up until 1 June 2006. It is NOT an AIS system BUT if AIS is on board (no distinction between Class A or Class B) then HARTS is not required. It uses GPRS (cell phone) channels to transmit the vessel’s position and identification information to the harbour authorities. There is no on-board display of other vessels … it merely lets Big Brother know where you are! It has a panic button for emergencies. Fine for non-compliance is $3500. For an FAQ go to

  12. Brian Lane says:

    Regarding operating AISs certified in other countries — I think there are international treaties that recognize the operation of the foreign equipment in US waters. I’m just guessing here, but its probably relates to the ship’s country of origin.
    I’m not sure why Mr. Pot seems to be so anti-Class B. He has done quite alot to promote AIS in the USA, as well as operating the website since before his creation of the SeaCAS. I’d have thought he would be supportive of anything that might help him sell more receivers.
    I wouldn’t be surprised if there were a bunch of politics involved in all this as well (Isn’t there always). Several years ago the US was hot to get a sub $1000 unit to market as fast as possible. They don’t appear to be pushing for that as hard as they were.

  13. Sandy says:

    If the FCC is anything like the Agency I escaped from, we’re getting pretty close to the happy ending. Items on circulation will get sniped at by the political appointees, but if there are no hot-button political considerations, they will get signed off, and then voted on. Two hundred commenters may sound like a lot to us, but I imagine they seen thousands of comments on a TV station renewal for just being a TV station! If there’s any foot dragging over this issue, its because we’ve ruffled some sensative and defensive feathers. Beligerance begets beligerance (sp?)

  14. Congratulations America!
    Yesterday USCG finally approved 3 more AIS_B. Pls see

  15. Ben Ellison Ben Ellison says:

    Kyasyo, I don’t see anything about more AIS Class B approvals at Navcen. Also I searched their database of approved equipment and still just see six approvals — SRT, ACR, Shine Micro, Simrad (Navico), Comar, and SevenStar. The search page is here:
    Some of these were Coast Guard approved almost 10 months ago. We’re waiting for the FCC, which is depressing.

  16. Fred Pot says:

    Implicit in installing a Class B transponder is that you
    send out your AIS target information and that doing so makes you safer. I
    believe Class B transponders make you safer but only because they are dual-band
    AIS receivers that enable you to make timely and appropriate evasive maneuvers
    to avoid a collision with a commercial ship and to contact a ship to make
    passing arrangement.

    About 70% of commercial ships piloted into US harbors do not have a radar or an
    ECDIS (or ECS) that can show AIS targets on screen because ship operators are
    not required to carry them. These ships have a 4-line “Minimum Keyboard
    Display” (MKD) mounted somewhere on the bridge but the Officer Of the Watch (OOW)
    is unlikely to monitor his/her MKD. He/she is primarily concerned about conning
    the ship in and among other large ships and about avoiding grounding on shoals.
    To do so he/she has to look out of the bridge window and also monitor a number
    of instruments to remain aware of his/her traffic and navigational situation:

    Radar for Range, Bearing, CPA and TCPA of nearby ships

    VHF communications with nearby ships and with VTS,

    Chart for own ship position and course through the channel

    Depth sounder

    Speed, Rate of Turn and Cross Track Error

    Numerous, frequent (and annoying) System Alarms

    Etc., etc.).

    Collision avoidance with recreational boats that are 0.2%
    to 0.02% of the size of a commercial ship is not high on the priority list.
    Commercial ships will make an evasive maneuver to avoid a boat but only if 1)
    there is enough time to do so, 2) the channel is wide enough and if 3) doing so
    doesn’t bring it too close to other (commercial) ships.

    More sophisticated commercial ships (Cruise Ships and
    Container Ships for instance), do show AIS targets on their radars and on their
    ECDIS. The OOW on such ships is specifically allowed to un-clutter navigation
    displays by filtering out less important targets and focus on what is important.
    Here is the language used in IEC62288 “Presentation of Navigation

    Filtering sleeping AIS targets

    191/ It shall be possible to filter
    the presentation of sleeping AIS targets (
    for example,
    by target range, CPA/TCPA or AIS target class A/B,

    NOTE  If
    display equipment provides facilities for the calculation of CPA/TCPA
    are independent of a shipborne radar target tracking system, then the facilities
    should comply with the relevant clauses of IEC 62388.

    If a filter is applied, then there
    shall be a clear and permanent or persistent indication, as appropriate for the application. The filter criteria in use shall be readily available to the user.

    191/ It shall not be possible to remove individual AIS targets from the presentation.

    Almost all MKD’s were installed on commercial ships
    (about 50,000 ships) by the spring of 2005. The Class B “CS” Static
    Information Messages (24A & 24B with the boat name, call sign, length and
    other static information) had not yet been defined by that time, let alone be
    incorporated in the software that interprets incoming AIS information for
    display on the MKD. It would indeed be possible to upgrade the MKD’s software,
    however, commercial ship operators are not required to do so and are therefore
    not likely to do it also because their bridge teams don’t make this a priority
    in their requests for equipment upgrades. Many MKD’s will never have their
    software upgraded.

    Only new radars and ECDIS will be able to display a Class
    B’s name and call sign. An old radar that is not able to display AIS targets
    can only be upgraded by replacing it with a newer model. You cannot simply
    upgrade its software. Radars are expensive and therefore will be repaired rather
    than replaced when they fail. The International Maritime Organization (IMO)
    requires that only ships built after July of 2008 carry “AIS Ready” radars.
    ECDIS carriage is still optional (and expensive).

    The displays used by USCG VTS personnel cannot yet show
    Class B “CS” Identification information. Class B will improve the
    effectiveness of SAR, provided that nearby ships, boats or SAR Aircraft can
    associate a Mayday or Pan-Pan call with an MMSI number, something that will be
    hard to do if their navigation display cannot process messages 24A & 24B.

    Installing a (stripped down) Class A transponder with its
    higher transmit power (12.5 W) more frequent position updates (2 – 10 sec.)
    and proven transmission of static and voyage related information significantly
    improves a boater’s safety. Much more so than a Class B transponder and well
    worth the additional cost.

  17. marinate says:

    I feel there are a few misleading points in Fred’s post:
    “ships have a 4-line “Minimum Keyboard Display” (MKD) mounted somewhere on the bridge”
    This is not true – the vast majority of Class A Transponders on the market have an LCD display with graphical plot of ships in the area. All of these show the position, speed, course and MMSI of a Class B vessel.
    Whilst it is true that Class B vessel name and call sign may not be visible on some existing equipment it is important to note (and enforced by standards) that the position, course, speed and MMSI will be visible. From a safety point of view this is the critical information from which the vessel can be located and contacted.
    “boats or SAR Aircraft can associate a Mayday or Pan-Pan call with an MMSI number, something that will be hard to do if their navigation display cannot process messages 24A & 24B”
    In a SAR situation a simple call to the local coastguard will retrieve the vessel name, call sign via it’s MMSI which will always be shown on the SAR vessel AIS display. I’m guessing the ability to locate a vessel in distress via it’s AIS transmissions is slightly more important than knowledge of it’s name?
    “Installing a (stripped down) Class A transponder with its higher transmit power (12.5 W) more frequent position updates (2 – 10 sec.) and proven transmission of static and voyage related information significantly improves a boater’s safety”
    The transmit range of a Class A transponder is typically 25nm, compared to 10nm for a Class B unit. From a safety perspective, nearby vessels are more important so the reduced range can’t be an argument here.
    With unfortunate incidents like this in the news:
    I imagine more large vessel officers will begin to take interest in AIS transmissions from small vessels.
    As prices for Class B AIS fall, I think it will soon become a ‘no brainer’ to fit an internationally certified Class B AIS device in place of a receive only product.

  18. Jorge Viso says:

    Fred is correct in his statement that most commercial vessels do not display AIS targets on a radar display. Most don’t have ECDIS or ECS so it’s not there either.

  19. Sandy says:

    Litigation is a sterner master than regulation. Should a large vessel collide with a Class B equipped yacht in some extremis, while blocking that yacht’s position data, the wolves will have a blood-feast. Careers will terminate. Fortunes will change hands. Thereafter, no one will turn their nose up at Class B.

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