The Offshore Voyaging Reference Site

Let’s Think Smart

Think icon

In the next few days we will be publishing the first of a series of posts from Matt, AAC Engineering Correspondent, on more efficient alternatives for getting the power of our diesel engines into the water to actually drive our boats forward.

In the first post he explains why we need to be thinking about this stuff: the bottom line is that most recreational yacht engines burn way more fuel and put way more carbon into the atmosphere than they need to or should do.

In the second and subsequent posts he has done a great job of explaining the advantages and disadvantages of each of the technologies available, or becoming available, to solve that problem.

Now some of this stuff is going to get a bit challenging to understand. And, horror of horrors, some of it will require a bit of very basic math…actually, so basic that it will be more arithmetic than math.

I’m going to guess that some of you are going to think “why the hell are you bugging me with all this complicated stuff? Just tell me what to do, and then we can go back to talking about fun stuff, like anchors.”

On the other hand, I have been able to understand Matt’s articles…after a couple of readings…OK three…and that’s my final offer. And I’m a dyslexic high-school dropout, so are you going to admit defeat before even trying?

Anyway, as chief editor (and office boy) at AAC, I’m going to subject you to this stuff for your own (mine too) good, here’s why:

Dumb Stuff Yachties Do

We offshore boat owners have a really, really long record of doing really, really stupid things because we can’t be bothered to listen to engineers and, more importantly, exert a bit of brain-sweat to actually understand what they are telling us. Here’s just a partial list of that stupid stuff (I have made ’em all but the last two):

I could go on for pages, but I’m sure you get the idea.

The point I’m trying to make here is that many of us made these expensive and even dangerous mistakes  because we succumbed to these lazy thinking traps:

  • I have always done it that way.
  • This is the way I want it to be.
  • This is my position and now I’m going to search high and low for a justification.

Rather than the right way to think, which is:

  • Think about the problem rationally,
  • do research,
  • make an effort to read and understand stuff from someone who has skills and training we don’t,
  • and then acknowledge the way it really is, even though we don’t like it.

By the way, you see a huge amount of absolute crap on the forums due to lazy thinking.

You don’t see much lazy thinking here in the AAC comments because our members are better thinkers and we have some really smart engineers around who pounce—actually they don’t pounce, they are really nice about it—when lazy thinking is exhibited. (Here’s an example, where my lazy thinking got me hung out to dry…quite rightly so.)

Dumb Stuff Humans Do

And the sad thing is that lazy thinking is not just a problem in the sailing world, it’s even more prevalent in the general world, particularly around a subject that is near and dear to my heart, environmentalism and climate change. That leads to really, really dumb stuff:

  • Buying electric cars with highly toxic battery packs and then charging them with electricity from a coal burning power plant. (It’s complicated.)
  • Totally discounting nuclear energy options even though huge gains have been made in safety and waste disposal since the current crop of reactors were designed some 40 years ago. (Before anyone has a melt down—ouch, sick pun—I’m not advocating for atomic power, just saying that we need to look at the options rationally—there are credible arguments that coal kills more people in a year than nuclear, including weapons use, has in history.)
  • Burning diesel to make ethanol to burn in a car.
  • Trucking stuff that should go by train or ship.
  • Not instituting a realistic carbon tax or cap and trade system—I’m not smart enough to know which is best but a simple per ton of carbon tax seems…well…simpler—while we have the chance due to the current lower oil prices.

The point being that lazy thinking is making us, as a species, ignore many easy fixes to our environmental and climate change challenges that would also help our economies if properly applied.

Actually, just fixing the last item in the above list will, I believe, automatically fix all the others.

So let’s start smarter thinking here at AAC by reading and thinking about Matt’s upcoming articles.

A Gym For Our Brains

Not only will reading said articles help us understand ways to save huge amounts of fuel and carbon in the recreation boat space, making the effort to understand them will exercise our brains and make them stronger at smart thinking. And better thinking leads to better boats, better cruises, and maybe even a better world.

…OK, that got a bit evangelical (where’s my white suit?) but I really do believe that anyone who has any sort of an audience, no matter how small, has a responsibility to talk about things that matter, at least occasionally.


Bring it on, this should be both fun and interesting!

Inline Feedbacks
View all comments
Dick Stevenson

Matt/John, Looking forward to the articles. Dick

Marco Rancourt

It is too easy in today’s age of (internet) information flooding to take bad decisions based on flawed arguments. I’m all about rational and critical thinking, and joined the AAC to have access to them. A little mind stretching doesn’t hurt anyway…

Colin Palmer

As an engineer (actually a naval architect) I look forward to some technical stuff. In that connection, I have been a lurker on this excellent website for a couple of years, but did intend to post on the anchor debate (and on painting aluminium – I have an Ovni). Many years ago I worked on wave energy extraction – we were designing moored, floating devices to extract energy from the waves of the North Atlantic. No mean challenge. I was lucky enough to spend many a happy hour working with 1:50 scale models in a custom built wave tank. It was like playing God, at the stroke of a keyboard we could dial up any sea state we wanted, from a nice average day to a monumental storm. In many ways, extracting energy was the easy bit. What was hard was to make the things stay in place at a reasonable cost. They had to have moorings that would withstand the one in 50 year wave, a 30m high monster if I recall correctly. The only way to limit the mooring loads was compliance – stretch in other words, and lots of it. With mooring rodes that were low stretch, the peak loads became astronomical, which would have required very expensive, heavy cables and massive seabed fixings. But by building some “give” into the mooring system the loads dropped dramatically. Based on that experience, I cannot understand why people use all chain anchor rode. There are very good engineering reasons for using low modulus nylon line, which will greatly reduce the snatch loads. I accept that anchored yachts are not (we hope!) subject to large wave action when anchored, but our boats do tend to shear around, which produces a similar snatch problem. So, yes it is important to try to limit the shearing (I have had some success with small riding sails on the backstay, but will try Colin Speedies’ drogue on the anchor line, which looks like a great idea) but that combined with a nylon anchor line is the best recipe I know for a good night’s sleep.

Frank Mulholland

I also have an Ovni and have been attacking the dreaded “bubbles” using advice from this site and other conversations. I would be very interested in your view/technique. Currently, I cover bare aluminium (immediately after abrading & cleaning) with standard West Epoxy. Then at a more leisurely pace fill/fair/paint…paint…paint.
Always interested in how different techniques last over time.

George Woodward

I .m just getting quotes to repaint my Ovni so I would be interested to hear your views. Below the waterline I am thinking of zinc (Zinga) before barrier coat, epoxy and anti foul. I think the inga provides an anode over the entire hull.

Frank Mulholland

Another vote for articles with more technical content. Even if it is contained in an “optional” appendix.

Colin Palmer

OK John, my reply re painting aluminium will go in the right place.

Gary Green

Addressing the comment about burning diesel to make gas for cars. If more energy is being put in to making Ethanol than Ethanol energy produced, then it isn’t a good thing. However if a lot less energy is put in to making Ethanol than the amount of Ethanol energy produced, then I think that is a good thing. The problem is that I don’t know the answer to this problem. One issue I have is when the government subsidizes the production of Ethanol when it can’t sustain itself. I can see government subsidizing to get a “kick start”, but that’s it. The industry needs to be able to sustain itself.

Drew Frye

To quote Al Gore (a self-proclaimed expert), when he came clean to the wire service on his position:

Al Gore, November 22, 2010:

“One of the reasons I made that mistake [over ethanol] is that I paid particular attention to the farmers in my home state of Tennessee, and I had a certain fondness for the farmers in the state of Iowa because I was about to run for president” in 2000.

In a twist of fate, it is probably one of the factors that drove the Saudis to increase production in order to regain market share and extend the age of oil.


Eric Klem

Hi Gary,

The ethanol debate is certainly an interesting one. The debate is really tricky because it has become heavily politicized and it has social affects too as some of the feedstock would otherwise be food.

With regards to the energy balance, not all ethanol is created equal. If you want to see 2 totally different ethanol models, just compare the US and Brazil. The differences come from what the fuel is made from and how it is processed. Corn, sugarcane, switchgrass, etc can all be used to make ethanol but with widely varying energy balances. My opinion is that there are compelling arguments for certain types of ethanol production but not all of them make sense and unfortunately, some of the ones that don’t make sense are the ones that are pushed the hardest.



Hi Eric,
Assessing whether Ethanol is a “good” fuel requires much more than comparing EROI of various techniques to that of fossil fuels. For instance if Brazilian sugar cane production involves cutting down rain forest and replacing it with sugar cane monoculture is the cost of lost capacity to absorb CO2 factored in? Or the permanent loss of soil productivity that leaves behind reduced biological habitat and capacity?

If corn from the midwest is the feed ethanol stock it will be watered by “mining” the Ogalla Aquifier. Thus one of the unaccounted costs of producing corn to fuel SUV’s (and boats) is a depleted capacity of the North American heartland to produce food for future generations. Of course it makes master sharecroppers like Monsanto rich in the short run.

Eric Klem

Hi Richard,

You are absolutely correct. We really need to be doing full life cycle analysis on all of this from many different perspectives. The energy cycle is a relatively easy one to talk about as we can use average numbers but things like deforestation, soil depletion, etc are difficult to pin down.


Gary Green

Here is another item that doesn’t make sense to me. It is related to the train derailments with cars containing hazmat. The news talks about making the cars stronger so they are less likely to release the hazardous material. But they don’t talk about just ensuring that the tracks are maintained so that there is no derailment. As far as I know, the derailments were due to faults in the track. Other countries have high speed trains that derail with a very low probability.

Roger Harris

“You see a huge amount of absolute crap on the forums due to lazy thinking”.

Perhaps. But my impression is that most of the nonsense posted online is not ‘lazy thinking’ but rather ‘out-sourced thinking’: i.e., people with neither relevant formal qualifications nor practical experience parroting thirdhand subjective opinions that they’ve read in a book, magazine or elsewhere on the ‘net.

Frederic Roy

About electric cars… This is and old issue, and just one more example of how the mainstream media quotes a scientific article out of context in order to:

1. Create controversy, and
2. support their funders (big oil, big auto, etc.)

The National Academy of Sciences is a reputable organization, and their Proceedings are respected in the scientific community. So, the problem is not with the article. It is solely with the biased/distorted media reporting.

If you bothered to go to the actual article you would see that the authors are focusing only on air quality human health impacts of 1. particulate matter and 2. ozone. They are not considering greenhouse gases that cause global warming (CO2 , methane, etc) except in a couple cursory references. And they are not considering other volatile organic compounds spewed by gasoline powered cars.

The EVs that they dont like are those that get nearly all their power from coal. This is a handful of states. For EVs in most states that get power from a mix of sources, they find to be cleaner than gasoline.
Here is a link to the article and the abstract:

Nat Acad of Sci Article on EVs and power sources:

Commonly considered strategies for reducing the environmental impact of light-duty transportation include using alternative fuels and improving vehicle fuel economy. We evaluate the air quality-related human health impacts of 10 such options, including the use of liquid biofuels, diesel, and compressed natural gas (CNG) in internal combustion engines; the use of electricity from a range of conventional and renewable sources to power electric vehicles (EVs); and the use of hybrid EV technology. Our approach combines spatially, temporally, and chemically detailed life cycle emission inventories; comprehensive, fine-scale state-of-the-science chemical transport modeling; and exposure, concentration–response, and economic health impact modeling for ozone (O3) and fine particulate matter (PM2.5). We find that powering vehicles with corn ethanol or with coal-based or “grid average” electricity increases monetized environmental health impacts by 80% or more relative to using conventional gasoline. Conversely, EVs powered by low-emitting electricity from natural gas, wind, water, or solar power reduce environmental health impacts by 50% or more. Consideration of potential climate change impacts alongside the human health outcomes described here further reinforces the environmental preferability of EVs powered by low-emitting electricity relative to gasoline vehicles.

Marc Dacey

Insofar as the electric car technology forms a Venn diagram with shore-independent cruising provisioning for the battery and charge sources, I would not consider purchasing an electric vehicle without investing equally in the means to create cleanly my own electricity. That means a south-facing garage roof covered in solar panels and a substantial rack of deep-cycle batteries with which I could charge my electric car, along with the customary related gear. Doing this exactly similar process on a boat in order to avoid buying and installing a generator has been very informative.