Furuno SC-30 satellite compass, so sensitive!

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.

15 Responses

  1. John Roberts says:

    There’s no doubt Navnet 3D is revolutionary technology and Furuno is rolling out the accessories like the SC30 to fully enable its capabilities. It’s exciting to me that small boat owners will finally get the advantages of a gyro compass in the form of an affordable satellite compass.
    I really want to comment on The Hull Truth; it’s truly became nasty and banal. Posters are threatening class action lawsuits, to go “Rambo” on the Furuno salespeople at boatshows, claiming Furuno purposefully hid information and deceived them and a bunch of other nonsense.
    I’ve been reading The Hull Truth for a couple of years, but I haven’t registered for a number of reasons. The thread about NavNet 3D is the ultimate example of why I don’t think I ever will!
    I just retired from 37 years of practicing law and I speak with some expertise when I say there is no basis for any class action lawsuit as some of the posters have implied. I attended the Miami Boat Show this year and a Furuno salesperson told me although all the NOAA vector charts were loaded, the project was not completed by the government. The Furuno rep stated the raster charts were complete and it would be some time before the vector charts were finished. So from my experience, Furuno was forthright. Having been into boating for over fifty years, I try to keep up on new technology and I knew that fact about NOAA vector charts, too. The information about NOAA vector charts was and is freely available. So the threats of class action lawsuits is bellicose grandstanding. Anyone that wants to pursue it will end up paying a lawyer attorney’s fees and then paying Furuno’s attorneys’ fees.
    I’m really, terribly shocked that people, who should be of means and presumably educated would publicly post threats against Furuno people. One poster states that, “I suspect they are going to take a lot of well deserved abuse,” at the Ft. Lauderdale Boatshow. Another replies, “I would go RAMBO on them if I spend that kinda of money!!!” That’s scary and, in my opinion, constitutes a credible threat. No one, absolutely no one, deserves to be abused or threatened. In my opinion, the hosts of The Hull Truth, need to shut down that thread and report the personal information of every poster who made a threat of abuse against Furuno people to the authorities. This isn’t about dissatisfied customers venting anymore, it’s not a joke and it is a serious crime.
    I’ve always had Furuno equipment on my boats. In dealing with this company and their dealers for many years, I’ve always been satisfied, although not always immediately. Sometimes, I’ve been frustrated; but, I never had to threaten anyone. It took a year to get the original Navnet right on my boat when it first came out. But Furuno always stood behind their dealer and product.
    John Roberts

  2. Russ says:

    I fully agree with John’s post. While I have a number of issues with Furuno’s handling of the NN3D roll out, and the current quality of the product (as I’ve previously said, they do not present the available vector data as well as some other programs present the exact same data), the organization has been very responsive.
    The response to almost every question I’ve posted on “Ask Furuno” has resulted in an almost immediate phone call to me. Personnel have not always had an immediate answer, but they have been very diligent in getting an answer. Other questions or issues that I’ve submitted to personnel outside the support organization have also usually received a timely response. Not always the answer I want, but I do get an answer.
    The SC-30 looks very impressive, and at least one reliable online retailer has it listed as available for $2,500, though they say it “ships direct” which presumably means direct from Furuno.
    While I”m sure fisherman are excited about how the SC-30 improves the fish finder accuracy, I’d like to know how much it would improve the performance of their autopilot, particularly under sail with a following sea.

  3. regina43_owner says:

    Thanks for ALL the GOOD information !!
    Please tell us something more about the MARPA radar functionality with or without SC-30 🙂
    Do you think an open 4 kw radar will be to heavy on a sailboat ? ( Radarmast ) ?
    I cannot find the weight’s listed at Furuno’s..?

  4. Butch Davis says:

    Reference THT and John’s comments. There is no reason to assume the participants are people of means and education. More likely there is a fair cross section of the boating community.
    As with many forums there are a several game players participating. They are certainly worth ignoring.
    I would like to see more participation by people with knowlege of both boating and marine electronics. Certainly that would add value to THT.

  5. praetorian47 says:

    Good post, John. I would disagree that there have been many actual threats on THT. Your example of “I would go RAMBO on them if I spend that kinda of money!!!” would only be a threat if that poster spend the kind of money he was referring to (presumably in the previous post).
    I don’t think Furuno reps are actually fearful of their safety at shows right now. This thread (which I have been following looking for some insights) is really just a small group of unhappy people being vocal.
    I’m a happy NN3D owner. I’m not thrilled with some of the issues I’ve had, but it is really new technology. To think that there wouldn’t be issues is just silly and ignorant.
    I purchased anyway, knowing the issues would come, but feeling secure that Furuno would address them as quickly as possible (understanding that that may still take a while)

  6. Russ says:

    Regina43: There are several 4KW units, both dome and open array. I have the DRS4A which is the 40″ open array on a radar mast and we haven’t seen any problems in up to 30 knots true.
    I’m sure if you submit a question on Furuno’s support site they’ll tell you the weight.

  7. JOE says:


  8. Liberty says:

    Do you know of any issues regarding mounting heights and the SC30?
    I have heard that it has to be mounted above any radar/VHF aerials which doesn’t ring true.

  9. s says:

    The previous comment raises an interesting question. I’m mapping a new system that has both an AIS Class A system (Furuno), a PB100 Weatherstation (Furuno), and a SC-50 compass (Furuno). They all want to be the highest point, and all want to be away from the radar. I’m just confused how it all works together.

  10. Ben Ellison Ben Ellison says:

    Yup…it’s easy for manufacturers to specify super safe antenna locations, then impossible for boats with lots of antennas to make all the specs work.
    But the proof is in the pudding. The SC-30 that impressed me so much was temporarily installed on the test boat’s little flying bridge, very close to lots of stainless steel and below a couple of radio antennas. I think it was within 6′ of the 40″ open array radar that was running all day, though slightly above its nominal vertical beam width. And in the picture above it’s below the boat’s entire superstructure, though maybe 8′ aft of it.
    I think the way to go is to plan an install as close to specs as possible, but leaving as many options as possible. Then test the hell out of everything before you truly bolt it all down, do the finished cable runs, etc.
    Or a get a boat big enough to fit all your antennas as “recommended”.

  11. Matt says:

    Ben, I have posted on here before and am a naval architect (friend of Gram’s), and some of these thoughts on installation position were a question for me too. When you install a fluxgate compass you want it on centerline, as close to the LCG/LCB/LCF as you can, and around the waterline. This would lead me to believe it is because you want the least amount of 6 degree dynamic motions to effect the readings.
    Now with this sat compass (and the rest) I sort of wonder how they work, and like people said, they are most likely going to be far from the center of vessel movement. Are the sat compasses literally trying to determine all 6 motions of the vessel relative to the fixed earth (GPS Satellites)? On top of that being very complicated mathematically (a Delft professor maybe solved that problem), how does that really help? Looking at the transducer example, depending on the location of the sat compass and the transducer, yes it may help with heave, but couldn’t it also hurt depending on phase of the motion of the transducer relative to the phase of the motion of the sat compass (thinking of pitch)? Or do you tell the sounder program the location of the transducer, and therefore crazy math (PHD naval architecture) determines the exact motion of the transducer relative to the overall vessel motion and subtracts it out, such as the transducer was standing still. Oceanagraphic research ships may do this, US Navy radar systems, but pleasure boats?
    Also, is the sat compass supposed to be a replacement for a fluxgate compass? And does everything that uses a fluxgate compass like the sat compass data as much? Radars? Autopilots? Or would there be a case where you would have both a sat compass and a fluxgate compass? Would you and could you therefore set presidence for which device (radar, autopilot, sounder, etc.) used which compass on the NMEA2000 network?

  12. Ben Ellison Ben Ellison says:

    Hi Matt, I have not seen the SC-30 install manual, but it would make sense that the best heave corrections would come with it mounted directly above the sonar transducer. I have heard from a U.K. installer who has tried one with a high end multi-beam bottom mapping system, and he says it does amazing compensation for boat motion.
    Yes, satellite compasses like this are replacing fluxgates and even gyros, though that does put more eggs in the GPS basket. But you can have multiple heading sensors on a NMEA 2000 network, and well implemented displays will let you prioritize which you want to use as a primary source. Almost every display I’ve tried will at least roll over to another sensor if the one randomly chosen fails. Easy critical sensor redundancy is one of N2K’s best features, I think.

  13. Anonymous says:

    Matt – you can find the SC30 brochure on the web on the web site of a least one retailer (though not on Furuno’s which is sort of odd) and it answers some of your questions.
    It does indeed use the comutational solution developed by the professor at Delft. Computation cost has dropped so much that I don’t know why a recreational boat couldn’t do the same calcs that were previously only affordable by the military, especially with a street price around $2,500, the price of a good notebook computer with screen, hard disk, memory, etc.

  14. Andrew Murray says:

    I know most systems that are using this for pitch, roll / heave compenstaion have a page to enter offsets to the SC-30 antenna and again offsets to the XDR (look in the navnet 3d manual if you have one)

  1. February 18, 2020

    […] sensors also calculate Heave, which can be used by some MFDs to stabilize sonar imagery, as I saw dramatically demonstrated with a $3,000 SC30 in 2008. The difference now is not just the greatly reduced cost; Heave is now a […]

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