Loading map ...

Recent highlights

View on large map

Latest Posts

General questions & comments
  1. Timothy Daleo says:

    Great looking new tender. Are you going to transfer your equipment over to the new one or buy new electronics for it? Hope the three of you are doing well!

    • Hey Timothy. The only electronics we have in the tender is a $100 depth sounder so we’ll leave that with the boat. As another act of partial craziness, I plan to install NMEA2000 depth, GPS, and even connection to the Honda 50. I’m not sure when I’ll get time to do all that work but we’ll get to it and I’m really looking forward to seeing that new tender next Wednesday.

      • jan-kees says:

        Since you are going to Harlingen to pick up the tender, enjoy navigating the Waddenzee. it is a great place to find a spot to dry out with low tide and check the hull.

        • This boat isn’t stable on it’s keel when dry so I wouldn’t want to intentionally ground it in a non-emergency situation. We’ll be careful on the way into Harlingen.

      • Timothy Daleo says:

        Good luck with the tender today. I look forward to seeing the upgrades in the future. I hope all three of you are doing well.

        • Got it as scheduled first thing this morning. It’ll do 42mph in open water with three people in the boat. I think we are going to really like it.

          We have a bit of a fuel pressure issue, I need to chase down but I doubt it will be challenging to solve. Otherwise, all good.

  2. Evan Bauman says:

    James – was reading about your NMEA network crashing due to low battery voltage. Curious to know why you have a separate 12v system when you could easily install a 24v-to-12v converter and power all of your 12v devices from your monster 24v system. Is there any significant advantage in having a separate bus?

    • I do have a 24 to 12v converter but there is also a battery on the 12V side to ensure that convert faults don’t take down the 12V bus. I screwed up and accidentally shut off the 24v to 12V converter. It’s easy to alarm on faults (or human error) and I’ll make that change so it doesn’t happen again.

  3. Tim says:

    Hi James:

    Looks like you are enjoying the British Isles!!

    On your Maretron I see you monitor battery state of charge, as do I, but separately for all four house banks and the start battery banks. As you know, the BSOC is a calculation from other parameters that the sensors measure. When we are at the dock, or in anchorages, the BSOC is working fine and moving up/down as it should during charge/discharge cycles. But when underway and the charge to the batteries is provided by the main engine alternators, the BSOC just declines till it hits zero. Maretron says it has to do with the charge efficiency setting, but I don’t think so.

    The main engine alternators are attached to the same bus as the batteries and chargers, and provide the charge to the batteries, as needed, depending if we are leaving the dock fully charged or exiting an anchorage with the batteries depleted requiring charging. However, once the batteries are fully charged, while they go into float condition with very little current going in/out as the alternators keep them fully charged (as noted by the voltage remaining steady in the 26.3V range with amperage fluctuating around zero on the house battery banks), the alternators DO NOT go into float as they are still generating power as required to fulfill the AC system demand through the inverter. As these components are all connected to the same bus, I am wondering if the four house bank current sensors are somehow sensing this load requirement to the AC through the inverters and assuming it is a draw on the house banks, therefore resulting in a calculated decline of battery state of charge, even though the batteries are fully charged and in float.

    Do you have this issue or have any thoughts on this?


    • Hi Tim. Good hearing from you. Yes, I recognize those two problems. They are both a bit challenging but both are addressable. Unfortunately, neither is a simple topic so this can’t help but be a bit longer than ideal for a blog question. I’ll answer it here but will end up filling it in and posting as a full blog entry.

      On the first question, battery State of Charge (SoC ), the best solution is not to use it. You are right that I display a state of charge in our system and I have invested quite a bit in getting a more accurate SoC report but it’s been a hassle and I’m pretty sure it’s not worth the effort. There are some proxies that are quite accurate and far easier that I’ll cover below. I’ll start with what I use instead and then we can circle back to why SoC is inaccurate and what I have done in an effort to get a more accurate reading.

      I use voltage and current as a proxy for state of charge when the system is discharging. The relationship between voltage and current is a complex surface (I’ll return to this below) but most of the time your boat is at a fixed, and not particularly heavy discharge rate. When there are no heavy, intermittent loads on your batteries and it’s just the steady background discharge rate, the voltage will closely match the discharge curves shown on page 34 of the Lifeline Technical Manual ( Of course, if you are using some other battery manufacturer, you must use their data but I’m using Lifeline as an example as they are a common choice and I use them on Dirona.

      If the batteries on your boat would need to be charged twice a day (likely) then you are on an approximate 24hr discharge cycle since they need to be recharged at roughly 50% charge. Assuming that you are on a roughly 24hr discharge cycle, you can use the 20 hour discharge cycle curve from that graph to get the relationship between voltage and state of charge when you have no big loads on your system.

      Of course the absolute most accurate approach is to disconnect the batteries and use the State of Charge vs Open Circuit Voltage on page 33 of the Lifeline manual. This is highly accurate but not practical on a boat during use. What I do is have battery voltage prominently display and learn to look when the system has no abnormal loads and the state of charge is a fairly accurate function of the voltage level with 24.2 to 24.3V being roughly 50% on a 24V boat and half that for a 12V boat.

      Why not just get SOC correct? The short answer is its really hard and every manufacturers SOC indicator that I’ve looked at measures the same things and has the same inaccuracies and these inaccuracies are so large under some circumstances that the SoC reading is close to valueless. What all commercial SoC calculators that I’ve looked at measure is the current leaving the battery and the current going back in. They know the charge efficiency (entered by the user) so they know how much extra current must go in to achieve a 100% charge. Just a bit more than what came out.

      Generally these systems are very accurate through a small number of charge/discharge cycles. But batteries are complex chemical systems and they transitions they are going through change over time and so the charge efficiency and, more important, battery capacity isn’t fixed and will change over time. Because they are tracking current in and out, even small errors become additive over time and the inaccuracies can mount quickly.

      The system can be reset by charging to 100% but the inaccuracies will creep back in as you go through charge/discharge cycles. You can work hard to tune the charge efficiency and you will get the commercial systems far more accurate but they will never be great. Consequently I use voltage at a known discharge rate as a proxy. It works well and is fairly accurate but it won’t work when the kettle is on (not the steady, background discharge rate you have calibrated for) and it won’t work when charging (not on the steady discharge rate).

      The voltage as a proxy for charge levels works fairly well and it works far more accurately than any commercial SOC measure I’ve seen so this is my primary tool. For generator autostart, I automate the finding of the fixed, background discharge rate by averaging voltage over 15 min and this works very well and yields a very precise generator start signal. In many ways, this completely solves the problem in that, if the generator starts when needed, I don’t have to worry about SoC.
      But, I couldn’t resist doing my own SOC calculations since I would like to be able to display that data accurately. If I display the SOC computed by using the 20 hour discharge curve from the Lifeline manual. This is wonderful and works very well but has a few issues: 1) it won’t show SOC during charging, and 2) it will not produce a reliable number if you are going through a prolonged heavier than normal discharge cycle.

      Since the data in the Lifeline manual appears fairly accurate, I decided to program not just the 20 hour curve but to also use the 1hr, 2hr, 4hr, 8hr, 20hr, and 120hr curves. I then curve fit the data to produce a 2 dimensional mathematical surface that returns SOC from current discharge rate and voltage. I implemented this and it mathematically worked fine but the Lifeline data at deeper discharge rates on used batteries is not accurate and ends up producing unstable results. My simple system of averaging voltage over 15 min and looking it up on the single dimensional 20 hour discharge curve actually worked better so I reluctantly ditched the complex multi-dimensional curve fit.

      But, I’m a sucker for punishment and I couldn’t leave SoC alone. Even though showing the function computed using the 20hr discharge curve and the voltage averaged over 15 min works very well, I still wanted to get a better SOC number. Clearly I should have left it alone but I would love to have accurate SOC even when charging and the discharge curve won’t help you under those conditions.

      I’ve invested some time in refining this and it is better than commercial systems I’ve looked at but the complexity wasn’t worth it. In this model I note that the commercial SOC calculation systems are very accurate at a few charge/discharge cycles but the errors mount over time and get less accurate. Once the batteries are returned to 100%, the SOC is re-calibrated, it again is accurate. Understanding this, I decided to use the commercial SOC number but calibrate it more frequently.
      Rather than just calibrating it at 100% charge, I use the 20 hr discharge curve and, since we know it is accurate when the boat hasn’t had any recent discharges, my automation waits until the discharge rate has been very stable for a long period of time and then corrects the SOC to match the 20 hr discharge voltage curve (actually a modification of it that slightly more closely matches the background discharge rate on Dirona). I then use this SoC bias to recalibrate the commercial SoC and report the commercial number with my bias. This combines the accuracy of the commercial SoC system computing current in and current out but corrects the system error that creeps into these systems over charge/discharge cycles.

      This synthetic SOC calculation is still not perfect but its good enough that I again show SOC in the N2kview display. The generator still is started on the 15 min averaged voltage which is simpler and seems very accurate but I display the SOC using the calculated bias as described above. Because I had a solution for the generator autostart years ago that works well and I’m used to reading voltage myself, it’s certainly not worth the work of trying to get SOC to work but that’s what I did.

      So, with that background, looping back to your question, should your state of charge be incredibly inaccurate? No, it should produce fairly accurate results for a handful of charge/discharge cycles if set up correctly. Make sure the Peukert function is correctly set for your battery type. Lifeline recommends 1.12. Make sure the capacity of your bank is set correctly. It turns out this is both very important to accurate SOC but they are also hard to get right. Bank capacity will fall slowly over time as the batteries are used. But, capacity will also fall somewhat more quickly as the system is taken through partial charge/discharge cycles. You eventually will need to equalize (Lifeline calls this “conditioning”) and, after each equalization, you will return more closely (but not quite) to your original capacity. The battery bank capacity is always changing and it’s very difficult to know what the current capacity actually is to accurate report SoC.

      As I said previously batteries are complex chemical systems that are changing all time so, if you get all these parameters right once, they will again be inaccurate sometime later. But, yes, you can get them right and get acceptable results for a period. I personally don’t find it worthwhile so just use voltage as a proxy and continue to work on the accuracy of my synthetic SOC calculation. Where I end up on this is recommending not to invest time in SOC and just use voltage with knowledge of the background, steady-state discharge rate. It’s a “good enough” data point and I find it’s actually excellent for driving our generator start signal.

      The second question you asked Tim was “Once the batteries are fully charged, while they go into float condition with very little current going in/out as the alternators keep them fully charged (as noted by the voltage remaining steady in the 26.3V range with amperage fluctuating around zero on the house battery banks), the alternators DO NOT go into float as they are still generating power as required to fulfill the AC system demand through the inverter.”

      It’s a great question. The short answer is that this can be “easily” solved by the charger and, for the alternators, the voltage regulator suppliers. If they measured the current going into the batteries then, with the voltage, they will know exactly the state of charge of the batteries and could fairly easily know the difference between supplying 75A to the house with the batteries taking nearly no current (high house draw with charged batteries) and the same 75A charge rate where 50A is going to the battery (Batteries nearing full charge but not yet there).

      However “easy” this might be, manufacturers of alternator voltage regulators and chargers don’t measure the current at the batteries and instead just measure the current output at the source (the chargers or alternators) and use this data as an estimate for what the batteries are consuming. For the reason you mention and I outline above, this often doesn’t work. A high house draw will look very similar to batteries still charging. I suspect that charger manufactures don’t like the installation complexity of measuring the current at the batteries so instead using the current at the source as a proxy for current at the batteries. In actuality, as bad as that is, most alternator regulators don’t even measure output at source. Instead they measure field strength in the alternator and use that as a proxy for current produced which is a proxy for current being sent to the batteries.

      Naturally, this approach doesn’t work well. It’ll work fine if the boat is just charging but if there are large house draws, it will compound the calculations. Some chargers like Victron Centaur ( use a time driven algorithm and run for 4 hours in bulk and absorption. These fixed time schedule approaches are a disaster and need to be avoided. Some like Mastervolt provide a vast number of parameters that can be changed but they essentially leave the problem up to you. This is not idea but, in the absence of measuring and using the current going into the batteries, this is best you can get and, although current isn’t known, voltage is known and this actually does give an accurate view of how close the batteries are to full charge. So, the data is there is get the system working right so if enough flexibility and tuning is offered, the system can be setup to work correctly and not abuse the batteries.
      On Dirona, we use a Balmar MC-624 ( to control each alternator and Mastervolt 24-100/3 battery chargers. Neither measure the current heading into the batteries but, since the voltage level goes up during the absorption phase, you can still tune these systems to use voltage as a proxy for charge level and get the behavior you want.
      What I did was reads the short Lifeline Technical Manual ( and program the Mastervolt and Balmar systems to deliver the closest match to what Lifeline wants under our usage patterns. I can share the configurations I’m currently using on Dirona as a starting point. It’s not quite as good as measuring the current flowing to the batteries but seems to work fairly well. The important thing is to not allow the system to go into bulk or absorption during high current consumption in the house and stay there for long periods on charged batteries. This is very bad for the batteries. Your two goals are to: 1) fully charge the batteries, and 2) back off to float and just feed your battery recommended float voltage the rest of the time.

      • Tim says:

        Hi James:

        Thanks so much for the response and detailed information. There is a lot to consume in your reply, but the jist of it is that I am likely correct in my assumption as to why the BSOC is not reading “correctly” while underway with the alternators providing the charge. I agree with you in that I use voltage and amperage as the proxy to ensure that things are working as they should an my experience over three years on the boat tells me that it is. I ran over this information with Lifeline and they concur. Like you say, without spending an inordinate amount of time on something that can be achieved in other ways, I will look at a few options before moving on to other issues.

        I will also take into account your comments on the other response related to Maretron for the ongoing management of the system. While I agree that spares can allow the system to get up running again quickly, some of the components are not cheep. For example, the one favorite that everyone seems to be having an issue with, the WSO100, is $1000. That’s not cheap for a chunk of plastic (I know there are some intricate things inside the plastic). Now I am up to three failures in three years, so I have you beat.

        PS….what are you doing up all night?!?!?



        • I agree that the Maretron gear is not cheap but it actually is relatively inexpensive compared to competitive monitoring systems. Your WSO100 at $1000 prices seems way high. You can have them for $566 on Amazon:

          I generally get 2 to 3 years from them. I took the last one apart to understand the failure mode and it was water leaking in between the top and bottom covers. I suspect they might last longer if nobody touches them when working up on the stack. I’ve been careful and it may make a difference. I’ve been told that the Airmar NMEA2000 weather sensor is more reliable but I’ve not seen it for less than $1,000 so I haven’t yet headed in that direction.

        • Chris Barber says:

          Hi Tim, as to your battery monitor perceiving constant drawdown while underway, are you saying that the current shunt that provides battery current to the BSOC is seeing the current provided by the alternator as battery discharge current? What I do is monitor current on the battery independently, so that if the alternator is supporting loads while the battery is in float and not asking for much current, the BSOC only sees the that tiny float current as charge (+) current to the battery and does not see any load current that is not coming out of the battery as actual discharge (-) current. i.e. it sees only the true charge and discharge current on the battery. Is that what’s making the difference for you?

          • Chris raises an excellent point. For battery SoC to have even a prayer of working the current transducer has to be between the batteries on one side and the charge source and house loads together on the other side. If the current transducer is between the load and the charge source, it’ll be almost random. And if there is load that doesn’t flow the transducer, the readings will be a mess.

            • Chris Barber says:

              Thanks James. I got the feeling that Tim’s current information was coming from the inverter or the alternator controller or something that wasn’t purely battery in / battery out. Tim, if we understand you correctly in this, this can be solved pretty easily.

        • Chris Barber says:

          I read “chunk” as “junk” three times before I got it right. Or did I have it right in the first place?

      • Chris Barber says:

        James, I couldn’t have said it better myself, with 30 odd years in the industry including a lot of hardware and software involved in BSOC!

  4. Sean says:

    From Falmouth: “The weird things is zinc life has been improving. They started looking good after 2 months, so we want to 3. Then they started looking great at 3 months, so we went to 4.”

    Is there any risk something else in the system has taken on the role of sacrificial anode?


    • The zincs are to protect the hydraulic heat exchanger. Since it’s not bonded or connected to other systems so I don’t think they can be protecting other components or other components can be protecting the heat exchanger. I suspect the reason the zincs are lasing longer is the boat has been underway less recently but it might also be the colder water.

  5. Mark says:

    Hi James, I am having trouble sourcing Lifeline batteries in Australia for our sistership to Dirona. I believe that you may have had a similar problem when you were in NZ. Your advice would be appreciated please?

    • Getting the batteries from the US will work fine for you but you will likely need to pay duty so you need to check on that cost as well. I strongly suspect buying the batteries from the US will still be a big win for you but you should check. When we were in New Zealand there was no duty since we were a visiting yacht.

      We bought the batteries from DC Battery Specialists ( Great company.

  6. Unspecified says:

    My (everyday) morning reading before the sun’s up starts with your site. Thanks for all the effort it take.

    Love your input if you have the time. I don’t think there’s anyone else I know that has the Maretron knowledge you guys do.

    Knowing what you do now, if you were building your Nordhavn now, which Maretron parts would you use to measure levels in all tanks – fresh, grey, black and fuel? I plan on leaving the standard measuring systems in place as backup and using the Maretron as primary.

    Also, there must be several options for installing these transducers. Given we’re able to place where absolutely ideal, where/how is that? Are they all installed on the botttoms of the tanks or on the access plates and lowered down? There must be a difference between installs on a new build and after market?

    • All of our Maretron sensors were added post-build. It’s probably easier and cheaper to do at the yard but they can be added anytime.

      For sensors, the WSO100 fails once every two years. Others reports the Airmar NMEA2000 part is more reliable. I continue to use the WSO100. The ultrasonic (read from above) tank level sensors don’t work well for fuel sensors and don’t work at all for black water. I’ve move my fuel level indicators to pressure sensors and the FPM100 and this works incredibly well. I’ve not yet moved the black water sensor but Maretron has a drop in submersible pressure sensors that is reported to work well. I’ll make that change when I next get an opportunity get parts from the US.

      Like you, we left the standard level sensors in place.

      We chose to have spares for all sensors on the boat to make it easy to deal with failures. Maretron is inexpensive enough that this is not very pricey and it makes managing any faults super easy. We also have an N2kmeter on board to detect physical NMEA2000 bus problems. It was useful in the first few years but we haven’t seen any problems for a long time.

  7. Patrick Downs says:

    I live vicariously through you and others! I just watched your YouTube video tour of Dirona and your automation of it. Amazing. Techies rule! (I am *not * one). I’ve spent the last two hours on Nordhavn’s website and reading about many of their boats in service. All I need is $$$,$$$. Safe travels—you’re living a dream.

    This video is great:

  8. Foster says:

    Baofeng UV-5R+, I love mine, the band coverage is amazing. Are you using Chirp to program yours? (And for some reason I thought you were a ham)

    • Yes, I’m using Chirp to program the Baofeng UV-5R+. It’s a really nice and easy to use program. Thanks to Andrew Dickinson who pointed me to both the Baofeng UVC-5R+ and Chirp.

  9. Rob Heath says:

    Hi Jennifer & James, Glad you seem to be enjoying London. We walked past Dirona on the evening of March 9th, she was looking great even though it was a horrible evening. For your information, the column in Trafalgar Square is Nelson’s Column, the statue being Admiral Lord Nelson not King Charles. Hope you enjoy the rest of your stay, and looking forward to following your travels this year.

    • We’ll get that changed. Thanks for the correction Rob.

      Since you are obviously in the area, if you would like to see Dirona on the inside, let us know.

      • Rob Heath says:

        Hi James,
        Thanks for the invite. We were in London for a seminar at the Cruising Association in Limehouse, we actually live in Leeds, Yorkshire. We had a good bar meal at the ‘Prospect of Whitby’ which also has a hangmans noose outside, overhanging the Thames. There is another quite good Italien restaurant near Limehouse, La Figa on Narrow St ( E14 8DN ). If you haven’t been there yet the Limehouse Basin is quite interesting, and quite a nice walk from St Katherines Dock. The basin connects the Thames with the inland canal system, and, as with St Katherines, has an odd mixture of seagoing and canal boats. If we are back in town while you are still in London we will be in contact – it would be lovely to meet you and Jennifer.

        • We’ve been to the Prospect of Whitby and liked it but haven’t done La Figa yet. We should do a walk down to Limehouse basin as well. Thanks for the pointers Rob.

          • Rob Heath says:

            We were quite quite amused this morning to see one of our beloved weather presenters doing the forecast from St Katherines Dock – Disappointed that Dirona wasn’t in shot though!! Have you made any plans for your trip to Amsterdam yet?

            • Cool. We figured it might be the local news. We’re loving London so have delayed our exit from here by two weeks. We’ll now be leaving around the 15th and heading to Harlingen Netherlands. We’ll pick up a tender we have on order in Harlingen and explore the area. From there we’ll head north to Heligoland Germany where we pick up a load of fuel and explore the island. After that, we’ll spend the summer in Norway and plan to winter in Amsterdam. We’ll be in Amsterdam for 4 months and plan to both enjoy the city and make use of the excellent rail and air service there.

  10. Chris Barber says:

    On the reliability of your Maretron system – have you experienced any runtime errors/crashes? It looks like you’re using the integrated display units rather than their black box system with separate monitors. I’m presently building a system around their MBB300 and the unit I have is spectacularly unreliable. it reports hard drive problems at boot up, and when displaying a page with a chart it will run for at most a few days before throwing storage errors and asking for a reboot. I had really high hopes for Maretron until I actually got my hands on one.

    I’ve been trying to work this through their tech support but not making much progress. I’m only posting about this here because I’m curious about your overall experience as a reference point. Mine could be an anomaly.

    • I use N2kview on a PC as the primary display for NMEA2000 data with IPG100 as the server and the combination is rock solid, never blips, never crashes, and never fails. I also use the DSM250 and DSM150 and soon will have a DSM410 in use. None have ever locked up or crashed. I use N2kview on numerous Android devices and, again, it’s solid and reliable without crashes or hangs.

      I have no direct experience withe the larger displays or the black box but I have heard reports that these systems have less capable processors so displays as complex as I use on my N2kview displays may not work on these devices.

      Based upon the level of frustration I sense you are having, I would try N2kview on a PC. I’ll just about guaranty you’ll have a good experience and will like it. This will allow you to know that the system can do what you want to do. Then you can scale back what you ask of the MBB300 to what it can reliably deliver without issue.

      Overall, I’m super happy with Maretron so, based upon the severity of the problems you are experiencing, I would suspect that you are either asking more of the MBB300 than it can deliver or you have a problem unit. I recommend trying a PC running N2kview and an IPG100 as a way to see the system running without issue and then you can work on the MBB300 specifically and narrow down the problem knowing the rest of your system is working well. The system on Dirona is stable, doesn’t crash, doesn’t hang, and there is a lot of gear interconnected. On that basis, I’m pretty confident you can get your system the way you want it.

      • Chris Barber says:

        James, great point on running N2KView on a pc. For sure it will always come down to the quality and capacity of the hardware. Good to know your system has been solid; I can’t believe that the near unusable state of the MBB is “as designed”. One page with two temperature charts crashing after a couple of days of recording. I’m going to keep pushing on Maretron. They’re probably hoping I’ll give up and go away so they don’t have to send me $1500 worth of new hardware. I was initially reticent to depend on a Windows PC for a significant and critical shipboard system but in this case… 🙂

        • There will be tasks for which your MBB is excellent but, it appears, you have found some limitations of that component. I personally would be tempted to return the MBB or use it in less demanding applications on your boat and install N2kview on a small Windows system. The PC/n2kview combination is known to work in more demanding applications and will avoid further frustration on your end. Life is too short.

          • Chris Barber says:

            And an undocumented one at that. If they’re really just running out of storage or failing to wrap a circular buffer (my personal guess considering the chart data is supposed to drop oldest for newest) then, well, I really would be left speechless. So far Maretron’s still giving me the silent treatment. Time for a phone call.

            BTW, have you seen these micro PCs like the Intel NUC? Most of them are Celeron procs, maybe some have better cpu, but super low cost with a lot of capability, and super small. examples here at amazon:

          • Chris Barber says:

            I just RMA’d the Maretron MBB after trying everything I could think of without sending it back to them. I just heard from them last night that my unit had been misconfigured when it was built with an 8GB SSD and loaded with a version of their software that does not support the 8GB SSD. So thumbs down for their ability to pay attention to what they’re doing, and thumbs up for figuring it out quickly once I returned it. They told me that the 5.x builds of N2KView do not correctly support this storage device (presumably this would apply only to versions of the software running on their hardware, not the PC version of it). They said it needed to have 6.x on it for the 8GB SSD.

            • Maretron support is pretty thorough and they generally get to the root issue. I’m glad to hear they got this one solved for you.

            • Tim says:

              Chirs…this is Tim on Piredmus, a Nordhavn 63. I have a medium density Maretron system, that is not as intense as Dirona, but fairly loaded. I am running an MBB200 and had been experiencing many hangs, freezes and other issues which I thought were related to the processor. After 2 years of Maretron blaming the installation, they finally started listening to me and worked with me for over 2 months as I collected data when the issues occurred to send to them for analysis. Previously I had changed the storage card as you suggested and listened to them complain that I had too many graphs writing to the MBB. That is what the system is built for!!!! While it is important to see instant data, data over time to track trends is just as important. After sending them this data and letting them dig into it they finally acknowledged an issue deep in the code. They rewrote the code and issued me a beta version to try before finally releasing the updated MBB software live. I have been running that steady now for about 6 months with NO issues that I was previously experiencing. With that said, I have had my share of component failures such that while I like the concept of the system, I debate its dependability. My failures in 2.5 years of operation include
               Coding issue causing display freezing
               DSM250 computer screen failure was replaced
               DST transducer defective
               One fuel tank sensor defective and replaced
               Two DCM100’s replaced
               A few temp sensors replaced
               WSO100 repaired after failure (and failed for a second time)

              Like I said, I like the concept of the system, but there appears to be a quality issue with components or something. I have a red phone hot line to tech support and am working through a few other issues now.

              • Thanks for the posting Tim. Over the years, I’ve come up with a few simple approaches to managing the Maretron system without needing to call support and some of these ideas may help you as well. My first observation is that the boat monitoring, alarming, alerting, and reporting world has been around for a very long time. Superyachts have helped develop this market and there are some very nice systems out there but they all have one common thread: they are very expensive.

                Some of these superyacht systems end up requiring a lot of skill to set up and can be service intensive. What Maretron has done is open this market up to folks that don’t want to spend $50k on a solution. I appreciate them doing that and, because their system is fairly cost effective, I can afford to have spares of all components on the boat. Everytime I purchase a Maretron component, I factor in the cost of the spare as part of my consideration. Even doing this, the cost of Maretron is still far less than the competitor and it sure makes correcting problems easy. If you were to replace any componnent on Dirona with a faulty unit, I could find it and fix it in minutes and without calls to support.

                At that point, it’s a solved problem from my perspective but, on more complex NMEA2000 systems like ours, I also recommend you get N2kMeter ( The meter will find physical network problems and, once they are eliminated, then finding a faulty component is easy. In actuality, most don’t need the meter. Once a physical network is installed and working well, you aren’t likely to see any issues but I still like having the meter.

                Almost all of the Maretron equipment on the boat has never had a problem and I fully expect it’ll work for the life of the boat. There have been a few components that cause problems and, on those, I find a different solution. For example, the smoke detector that Maretron initially offered as an accessory to the SIM100 can produce false alarms in a hot engine room. I replaced that part with one from a different supplier. Maretron didn’t have some of the pressure sensors I wanted with the FPM100 so I get what I want from Setra. The WSO100 fails every 2 years and I really should find a different supplier but haven’t yet. I’m told the Airmar NMEA2000 part works very well.

                Generally, the technique of not continuing to use those parts that aren’t producing sufficiently reliable results and having a full set of spares on board has worked fairly well for us. After 8 years of operation, I’m still happy with the system and view it as good value even though I still do replace the WSO100 every 2 years :-). Using the tricks above, you can fix any problem in the network in minutes. I’m quite confident you can get your system stable, reliable, and easy to manage and yet still keeping it cost effective.

                • Chris Barber says:

                  And fortunately most, if not all, endpoint sensor functions can be found from multiple sources. It’s the processing nodes that we’re stuck with from Maretron. Running N2K view on a PC is very wise; I didn’t think so at first and bought into the black box solution seeing it as most cost effective. I’m not so sure of that now but I have to agree that it would be difficult or impossible to find equivalent functionality elsewhere for even money. As a software guy, I can easily conceive of writing all of my own apps from network layer to UI to run on top of the device network and bail on N2KView completely but I also know that the value of my time to do that would make the cost of N2KView and it’s hardware look like a trip to the Dollar Store. Even so, I was so pissed last week that I started building an app to catch and display all the N2K traffic from my USB interface. Like you, I’m a glutton for punishment!! 🙂

                  • Yes, I agree, there are lots of ways of getting data including using embedded computers like Raspberry Pis that can monitor non-NMEA2000 sensors. I have a bunch of DHT22 temperature sensors deployed throughout the boat. But, as you said, if you value your time, just go with the packaged solutions from Maretron. They work well, the are economically priced, the N2kview display system is incredibly flexible and easy to use, and boating should be about enjoying the boat and where you are rather than programming embedded systems and PICs :-).

              • Chris Barber says:

                Hi Tim,
                Wow, I really feel for your frustration! Thanks for the war story on this and it sounds like our “new and improved” version 6 is the direct result of you exposing the weakness in version 5. For sure, software which is built to log data needs to withstand the rigors of that job. It needs to comprehend and manage its own limitations in capacity, throughput, etc, and communicate this effectively to the user. Running out of storage or blowing out of the end of a circular buffer or whatever and just running off the road is not an acceptable design. I’ve spent most of my career designing hardware and software for embedded system much like what Maretron uses for their rig and I think I have a good perspective on practical design. I commend you for pushing on Maretron until they finally got it.

  11. Lucky Read says:

    We currently live on our Spindrift 43 sailboat. But, do to my wife’s back problems, which are exasperated by constant healing. We are seriously considering exchanging our beloved Chrysalis for a trawler. We especially love the Nordhavns.

    Not that any of that has anything to do with this comment.

    Anyway, I just wanted to tell you how much I love your informational posts. So clear, easy to understand and thorough.

    Really enjoyed your latest Fender Post.

    Thank you for sharing your knowledge and insights, and your logical “WHY’s” behind how you approach and solve problems.

    Keep up the good work.

    • Sorry to hear that it’s a medical issue that leads you to lean you towards considering a trawler but, whatever the reason, our experience has been that a Nordhavn isn’t a bad choice and we have ended up covering a lot of “ground” and really enjoying it. Thanks for the feedback on the blog and good luck on your “next boat” selection.

  12. aniruddha apte says:

    Hi James & Jennifer: I stumbled onto your site when reading about aws datacenters. Great writing, great courage and great seamanship !!

    The link text:
    “The economics of sea freight” pointing to “http://localhost/MVDironaBlogTestSite/2013/12/21/TheEconomicsOfSeaFreight.aspx” on page // is broken.

    All the best,
    aniruddha apte

  13. Colin Rae says:

    Hi James and Jennifer,

    Can you remember how much fuel was in Dublin when you filled up last year please?

    Many thanks,


    • The fuel was sold by Karen Brady of Campus Oil ( and delivered by truck to a commercial dock. They produced the best price by far in the region and delivered good, clean fuel on time. Karen is at Fuel prices swing all over the place over time and taxation position but, back when we made this purchase, we paid something just under 0.60 euros per liter. I recommend checking in with Campus Oil.

  14. Erik Jacobson says:

    Hi James
    Thanks for your advice on how to add Maretron Temp monitoring of the hydraulic fluid reservoir.
    A couple of other queries, how and where did you attach the TRK3 probe to the reservoir. I see the sensor cable is 10ft and that adding an extention cable to get to the pilothouse where the TMP100 is will affect the accuracy of the probe at upper temp range. How did you address this issue or is adding 25ft more feet of low impedance cable not going to make much difference to the high end temp.
    Lastly, I will fit a maretron display (just a small one as dont have much console room left) that is always on due to the importance of data like this temp reading. Are the DSM150 and the DSM250’s rock solid in reliability in your experience.
    Regards erik

    • We ran a NMEA2000 cable through the boat and have Ts spread throughout the boat: 1) at the back of the ER, 2) front of the ER, 3) hallway between staterooms, 4) PH, 5) fly bridge, and 6) bottom of stack. I put the sensor/actuator units close to what they are operating upon. In the case of TMP100s I have 1 at the back of the ER and one at the front (only need two because I’m using all the channels). If you put it in the PH, you might need to run 8 wires to support the 4 sensors on a TMP100 (and more if you are using the thermal couple connections). I wouldn’t recommend runing 25′ of cable down to the hydraulic reservoir.

      I use both DSM150s, DSM250s, and I’m about to start using the new DSM410 that has replaced the now discontinued DSM150. All have been reliable. I strongly recommend that you put a IPG100 in your network. With an IPG100, for no extra charge you can run N2kview on mobile devices and, if you chose to at extra cost, you can run n2kview on your navigation computer.

      I attach the TRK3 to the hydraulic reservoir by unscrewing a single bolt holding a fitting to the tank and putting the TRK3 under the bolt and washer to get a good mechanical connection for accurate temperature sensing.

      • Erik Jacobson says:

        Ahhh, your idea of placing TMP’s close to where they are needed is a good idea and i wish that had happened on my boat alas, it didint so now I will have to workout how to deal with this. I have a NMEA2000 backbone down the length of boat so no problem there and I see a maretron labelled box in engine room whidch I have yet to open and see what that does but it isint a sensor termination box. Adding another TMP100 to the engine room as you have done solves this issue.
        I have an IPG100 and using a Samsung 10″ tablet with N2KView and it works great but I also like the idea of the dedicated maretron displays in critical places like PH and one in master cabin. Less to go wrong than with a PC. I looked at specs of the new DSM410. From what I can see, they do the same as the DSM250. Why would you go with a DSM410 over a DSM250 James?

        • Evan Bauman says:

          For what it’s worth, I have both the DSM-410 and the DSM-150 displays. Other than the size, there is very little difference. The DSM-410 buttons are not traditional buttons and their tactile feel is a bit less than satisfying. The DSM-250 is a bit larger than the 410 and quite a bit more expensive. Not sure the price difference is worth it.

          • I bought the DSM-250s before either the DSM-150 or the DSM-410 came available. I agree the DSM-150 is better value and it’s a nice overall easy to use package. I just got a DSM-410 that I intend to use in the new tender so I haven’t yet any hours on it but screen looks very nice. I think it’ll work well.

            • Erik Jacobson says:

              Thanks guys. That help me make my decision on what to order.I thought the DSM 150’s looked good value too but difficult to find now so may have to contend with the 410.

              • Good plan. I have 2xDSM250s and 2xDSM150s on Dirona and I just bought a DSM410 for our new tender that we’ll be getting soon. We’ll soon have some experience with the DSM410.

  15. Steven Coleman says:

    I have often wondered when I see charging adapters plugged in for your electronic devices why you don’t install some of these, or something similar. I’ve always wondered if they weren’t as good an idea as I think they are. I’ve got some Leviton receptacles in the house that “seem” to work fine for the cellphones (Android) and the I-Pad used for work. They aren’t cheap, probably more than an adapter, but I installed them in our master bedroom so I could charge our devices without giving up one of the duplex outlets on the receptacle.

  16. Richard Koller says:

    Hi James
    I’ve reviewed your electronics diagram and am impressed by your redundancy. I have a couple of questions. One in regard to your choice of a class A AIS given the price difference. The other is how to contact your electronics person. Finally, do you have an SSB radio?

    • Emerald Harbor Marine in Seattle did the original electronics installation on Driona back in 2010. It’s still operating well today. Contact Larry Schildwachter (cell phone 206-793-7950, and feel free to ask questions here.

      We chose a class A AIS rather than class B primary because these targets are paid attention to whereas class B is sometimes, hopefully rarely, ignored. In busy ports some commercial operators only display class A targets. It’s not a huge concern for us but, for a small added bit of protection, it felt worth getting the class A.

      We originally intended to get a SSB radio but eventually decided not to. What pushed us towards not bothering is we have a business need to be connected all the time so we have a KVH V7hts mini-VSAT system that is connected 24×7. If it is blocked, out of range, or develops a fault, we fall back to Inmarsat BGAN as a backup. As a third level of defense, we have an Iridium handset as well. With all this satelite gear we felt well connected and, friends of ours have had lots of trouble getting electrical interference problems solved on their SSB — modern boats can produce a surprisingly large amount of interference. It’s all solvable but it can take work and, in the end, we just felt we had the connectivity we needed without SSB or HAM radio so we ended up not installing a HF radio.

  17. Paul Wood says:

    A wee bit of useless trivia regarding the freezing conditions. In February 1814 the river Thames froze and the ice was thick enough to hold a frost fair on the river. They even had an elephant walk across the frozen river at Blackfriars Bridge!

  18. Andy Biddle says:

    James & Jennifer,

    Looked at the weather for London because my son is headed there with his university class. Wow…cold and snow. Looking forward to some pictures.

    • David Andrews says:

      With reports of sea ice at Cowes on the Isle of Wight and frozen canals elsewhere in London, I wondered if you have had ice forming in St Katherine’s dock?

      • No ice around here but lots of snow. The water is 43F (6C) and the air temperature is 29F (-1C). The combination of low water and air temperatures has our reverse cycle heat systems on the verge of not operating. A couple of the 5 units won’t heat the air until the air temperature in the boat gets up into the 60F range. Once they “catch” they work fine but they aren’t reliable first thing in the morning so we switched to the diesel furnace.

        This morning we took the tube to Kings Cross station planning to take the Virgin train north to Leeds and then continue to Carlisle. We thought it would be a great trip with all the snow on the ground but the train was canceled. We could have made the next train work but the weather report continues to deteriorate so we decided to put the trip off until the snow stops.

        As I write this, it’s lightly snowing at St. Katherine Docks and we’re surrounded in snow. It looks just great.

  19. Mark McGillivray says:

    I was advised by the first (inept) Yanmar mechanic I had work on our boat that the reason for the black smoke and oil pushed out from our Yanmar wing engine, a 3GM30FV, is that it is overpropped. However, I have asked a propeller specialist to size a propeller for our boat with this engine and he essentially has calculated what we currently have. Our engine specs are: ​Cont Rating 17.7 KW @ 3400 rpm, Max Output 20.1KW @ 3600 rpm, Transmission is a KanZaki, Model KM3V, ​Gear ratio 2.61.
    At revs lower than 2500 rpm the engine sounds and performs great. Because the engine produced copious amount of smoke and oil slicks, at revs above 2650 rpm, we limit our revs to 2500 rpm. As the engine appears to be able to rev higher I suggest that changing the prop would be premature and that we should have the engine looked at.
    Before I enlist another diesel mechanic to look at our problem, could you suggest what areas could be responsible.

    • The easiest test is to see if you can turn above rated RPM at full load in gear. In this case, that would be 3600 RPM based upon what you have said above. You need to be able to attain at least 3600 RPM in gear and you would prefer to see a bit more. If you can’t get this RPM, you are likely over-propped. On Dirona, we have a lot of gear on board so we reduced pitch in both our main engine and the wing engine to be able to achieve full rated RPM.

      In what’s above I said “likely to be over-propped” because it is by far the most common problem but, to be complete, there are many engine problems that can prevent full output. For example a plugged air filter, restricted fuel system, or a stuck turbo. If the engine is operating correctly and you can’t get full rated RPM in gear, it’s over propped. Boats usually get heavier as they get older and engines can slightly lose power over time so it’s quite common to need to reduce the pitch of a prop during the life of the boat. I did it twice on our previous boat and it’s been done once on the current one.

      The tables that allow a prop expert to tell you the pitch that should work are a good starting point but they are only a starting point. The reasons why props often need repitching is the tables are only a starting point. It’s not uncommon to find these estimates off by a 1/2″ of pitch and even more is possible even when working with a very experienced prop shop specialist. In the end, the “right” pitch is the one that allows the engine to reach full rated RPM underway in gear when the engine is in good tune (clearly if the engine isn’t running properly, repitching isn’t going to help).

      That’s the quick summary. More data here: //

      I’ve got a picture in this article that you might recognize: //

      It’s super important that you get this condition fixed before extended operation. Black clouds from a diesel are often the precursor to large repair bills.

      • Mark McGillivray says:

        Very good reference articles James, thank you. Our existing 18″ 2 blade propeller has a 9″ pitch. This is already getting very fine. Although one engineer recommended a 18″ x 9.75″ (larger pitch), another has recommended machining the blades to 18.5″ x 7″. However, I am hesitant to change until I can have someone look into the oil, not just the black smoke, that is being thrown out above 2650 rpm. One engineer I spoke to thought that a seal or gasket could be leaking at these higher revs and pressures.

        • I just about guaranty you are over-propped if the boat still has the original pitching. However, as you are thinking, getting the engine right is the correct first step.Once you have the engine running well, you can do the wide open throttle test, find the pitch needed and make the change. I was able to get the blades on our Gori prop repitched by Kruger Props in Seattle rather than having to replace the individual blades of the folding prop. They did an excellent job.

          Tell me more about the oil being sprayed out. Is the oil comming out in the exhaust water or leaking from somewhere on the outside of the engine?

          • John says:

            oil or fuel oil? Sounds like the injector pump might be a problem?

          • Mark McGillivray says:

            Definitely, oil coming out with the exhaust leaving an oil slick beside/behind the boat. Finding a good diesel mechanic that is available is proving very difficult. I spoke to Martec In the states and as a result, I will get the blades set to 17.5″ x 7″ and work from there.

            • You will get a bit of oil on the surface of the water when some diesels are cold and, in some engines, there is always a small bit of fuel on the water at idle. Lots of fuel on water indicates the fuel is not fully burning. It might be over-fueling caused by overload or there might be an engine problem like a bad injector or a bad cylinder. I would make sure the engine can turn up to fast idle (full RPM without load) and, if it can, I would put the engine under high load (doesn’t have to be wide open) when under way when under way and check the temperature of each exhaust runner. What you are looking for is to ensure that each cylinder is contributing and around the same temperature. A dead cylinder will read cool. This is a rough test but it’ll tell you if all cylinders are firing and contributing.

              • Paul Wood says:

                A film of black carbon on the transom/surface of the sea with rainbow staining is likely to be partially burnt particulates and unburnt fuel, indicating an overloaded engine.
                An easy way to check for engine overload is to slowly increase the throttle, if at some point the engine revs cease to increase but you still have some movement (forward or reverse depending which gear you’re in) left on the throttle then the engine is overloaded indicating a prop / engine power band mismatch. Possible causes are fouled bottom affecting hull speed through the water, partially blocked engine breather, air filtration or exhaust. If the exhaust is clogged with sooty gunge due to the engine being run at half load for a prolonged period (like a bus going uphill throws black smoke under heavy load) this may show as temp increase, I’d wager it could even throw an alarm light. James has covered the injectors but I’d check the simple stuff first.

                • Mark McGillivray says:

                  Thank you James and Paul,
                  With the information you have provided, now, I feel much more confident in the diagnostic avenues to take. The blades have been sent to Sydney, NSW for machining. I expect them back late next week. I will keep this blog posted.

  20. Steven Coleman says:

    I use a lot of storage boxes on my service van. One I like is this style by Plano They come in a variety of sizes and the actual latch is perfect for my use. I’ve dropped and cracked them but I’ve never had one come open and spill. Probably the only drawback is the dividers are removable and can come out or shift letting small parts shift but superglue deals with that.

    • We have a few Plano boxes on the boat and like them. They seem durable and work well. The one you pointed us to is pretty low cost as well. It’s about 1/2 of what we paid (things are a bit more expensive here in the UK) and it looks a bit stronger. As always, thanks Steve.

Leave a Reply

Your email address will not be published. Required fields are marked *