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Text and photos © 2014 Steve D’Antonio Marine Consulting, Inc.


Congratulations on your latest professional move.  It leaves me a bit disappointed with PassageMaker in not supporting your independent writing.

I have a Holland 38 with a Volvo D6-435 engine that was launched in 2009.  I’ve noted that the engine is not particularly accurate in reporting fuel consumption.  I now have 655 hours on the engine and have kept records of fuel consumption as reported by the engine computer and also of fuel purchases.  The totals now are 1516 gallons consumed per the engine computer and 1763 gallons purchased.  This works out to an error of 14% over the life of the boat.  I think there may be some correlation with the magnitude of the error and the amount of operation at low speed.  We often cruise at 8-8.5 knots, about 1400 rpm and reported fuel rate of 1.5 gal/hour.  Volvo service (at least the contacts I’ve been able to access) seem surprised at this result.  They typically see errors in the other direction and generally less than 5%.

Two questions.  First, should I be concerned about a problem with the engine?  Operation seems perfectly normal in all other respects.  Second,  the industry now uses engine reported data in test reports of new boats.  As you might imagine, I’m somewhat skeptical of this data.  Is this good practice or are the engine manufacturers biasing the reported data to make their engines look more efficient?

Perhaps this is of general interest.  I assume I’m not the only one who’s noticed this issue.


Charles E Hillman


You are not alone, fuel consumption data is most assuredly an area where I’ve found fault in published boat reviews, and an area where I have heatedly disagreed with editors for publishing them.  In many cases publications report fuel consumption as factual, when in fact, what they should be saying is, “The engine’s instrumentation reported fuel consumption of X.X gallons per hour at X knots”, or, “The boat builder reports fuel consumption of X.X gallons per hour at X knots”.  Unless the fuel consumption was verified by empirical testing, it’s theoretical.  I have no way of knowing if engine manufacturers or boat builders are stretching the facts, or if this is simply happenstance, however, I have personally encountered electronic engine displays that indicated fuel consumption rates that beggared belief, and this is particularly so at idle and low cruise speeds.  My recommendation is to take indicated fuel consumption rates, at these low speeds, with a healthy degree of skepticism, particularly if they appear too good to be true.  I once remarked to a colleague, in jest, after reading one such review, “Based on this fuel consumption data, this vessel might actually make fuel”.

Rather than using a fuel flow transducer, like a FloScan product, fuel consumption rates indicated by modern, electronically-controlled diesel engines are derived via the engine’s computer management system, taking into account rpm, load and other factors.  The computer crunches these numbers using algorithms, and then produces a calculated fuel consumption rate.  Typically, they are very accurate, however, and once again, at the low rpm range, I have encountered seeming inaccuracy.  Assuming your engines are in good working order otherwise, and assuming they are properly matched to the installed propeller and achieving rated wide open throttle, I don’t believe this is worthy of concern, at least not from a mechanical perspective.



Hi Steve,

Question:  To your knowledge, is there a single website where boat owners (consumers) can share their observations in a formatted, focused, and arbitrated manner on marine products and services?  For example, boats, products, boat yards, contractors, etc?  Kind of a Yelp for boaters?

I’ve searched, albeit minimally, and can’t seem to find something that is narrowly focused in this regard. It would seem to be an opportunity for a “great equalizer” in the industry.

There are a lot of details surrounding such a concept (like counter response from those that are rated/reviewed) and moderation of posts, but regardless, it seems like a potentially valuable device that I’ve been giving a lot of thought to.


Cedric Rhoads


This is a question I’ve been asked by many clients and readers, and I agree, there would seem to be a need (and a market, how could the administrator of such a site make it profitable, with ads perhaps?).  There are forums, as I’m sure you know, however, they don’t meet the criteria you’ve spelled out, which would be necessary for this to be truly unbiased and successful.

It would be time consuming to moderate, and the moderator would require a deft, diplomatic touch, knowledge of things mechanical, and some marine industry business experience.  This may require the skills of more than one person, a moderator and tech advisor perhaps.  And, you are spot on, providing those who have been evaluated an opportunity to respond, a la Trip Advisor, would be very important.  It’s a tall order, however, with the right folks it may be achievable and it may be profitable.

Since I initially answered this question I did recall one such site   I haven’t used it other than perusing it from time to time, so I’m afraid I can’t rate it myself.  Worth a look perhaps.




I have an old Viking which has 2 of the bulkhead fuse holders you have pictured on your website. Do you know who manufactured them? Do you know who could have any? Although I completely understand your position on their faults I am limited on room. If you know of another product which occupies the same space please let me know.

Best Regards,

Douglas G. Ohrtman


There are hundreds, perhaps thousands of these clear plastic, weather deck bulkhead-mounted fuse holders in use on various makes of vessel.   I’m afraid I don’t know who manufactured those fuse holders, however, I’ve seen and replaced many.  In addition to their tendency to disintegrate, corrode and overheat, fusing individual legs of 120 or 240 volt shore power service is dangerous, and it does not comply with American Boat and Yacht Council Standards.  If one fuse blows, and the other does not, the resulting power supply could lead to equipment malfunctions, overheating and potentially fire.  Substituting a simultaneous trip two pole circuit breaker, elsewhere, below deck (where there is plenty of room), would make a lot more sense, it would be safer, it would not be very costly, and it would be ABYC compliant.  You insurer may also prohibit use of this type of fuse arrangement.  The old, abandoned fuse holders could be left in place to simply fill the holes.

Having said that, because these fuses were used extensively by Grand Banks for many years, you might have luck Google searching that or contacting a dealer for a replacement.  Again, retaining this arrangement is neither safe nor ABYC compliant.