Fuel flow and economy - Marinaut 215

C-Nile":z6dr0nhj said:
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5) using the fuel flow meter to determine optimum efficiency settings. I can't tell you how many times I subjectively think I'm running efficiently until I objectively look at the fuel flow and see how inefficiently I was traveling. <more stuff clipped>

I think that aspect is key and applies to many boats, cars etc. Nothing helps to modify behavior more than accurate data and real-time feedback.
 
Here are some real world numbers from my trip to Alaska this summer. Honda BF90D, C-Dory 22 Cruiser, no bottom paint. Fairly heavy load most of the time. 1-3 people, food for a few weeks, big ice chest with up to 50 pounds of ice, up to 70 gallons of gas and 8 gallons of diesel, 6hp Tohatsu kicker, three group 24 batteries, dinghy, inflatable kayak, extra anchor and rode, and all sorts of other gear. And by the end, a somewhat dirty hull.

Anacortes to Ketchikan: 74.2 hours, 805.4 statute miles, 10.9 mph average speed , 219.3 gallons of gas, 3.67 miles per gallon

Cruising in SE Alaska: 279.9 hours, 1,978.5 statute miles, 7.1 mph average speed, 413.7 gallons of gas, 4.8 miles per gallon

I don't have the numbers for the return trip from Ketchikan to Anacortes yet because the boat hasn't been filled up with gas again, but from Ketchikan to Lund, BC they were: 108.4 hours, 740.7 statute miles, 6.8 mph average speed, 152.2 gallons of gas, 4.9 miles per gallon

Hopefully I've got all these numbers added, divided, and multiplied right...

Rich, what was your actual average speed during the last 963 miles? Just miles run divided by hours run. That would be helpful in comparing apples to apples. I've found that even if you cruise at 16 mph, the average including coming and going from marinas, anchoring, etc. is much lower.
 
Retriever,
Your are dead-on. My best estimate is 10.8 miles per hour, which ironically is very similar to your run for Anacortes to Ketchikan, but I'm getting 4.6 mpg -- not 3.7 mpg. It must be that your boat is heavier, and you were traveling in more harsh conditions. Even so, that is good mileage for big water, and it confirms, I think, the great efficiency of the CD 22.

My 10.8 mph YTD average number does not mean as much as one might think, particularly for which to draw conclusions. If I said I traveled 6 miles per hour for two hours, one might conclude that I might be getting 6 mpg or higher, and that would raise overall mileage levels to present a more favorable view. However, what if that 6 miles per hour was through 4 foot seas with wave periods of 2 seconds in which I was only getting 3.5 miles per gallon? This has happened to us. What I'm getting at is that an overall mileage figure is akin to taking an average of the averages. Next season, I'll take down precise engine hours for a certain period, and include fuel flow numbers and miles travelled for different legs of the trip. It's a lot of work, but it would be satisfying to see the numbers and share the results without taking an average of the averages.

To shed a little more light on my area and travel habits, our average trip is 45 miles. The waters we travel upon, while choppy, are well-protected. In ideal conditions, our trip would include a total of 2 miles departing and returning to our marina at 6 mph, slow-no-wake speeds to get to Long Island Sound. Travel 41 miles at approximately 20 mph at 3500 rpm on the Sound, with the tide and/or wind either running with me or against me (but we try to go out in favorable conditions and stay home when the winds are up.) Travel 2 miles at slow-no-wake to go into/leave a transient berth or anchorage.

When the seas are around 4 feet or higher, we either head home if it is a short distance or look for a safe harbor, and our speed is between 4 and 7 mph. We were heading past Orient lighthouse a few weeks ago, and I estimate wave height at 4.5 feet initially. A 42 foot sailboat turned back. We almost turned back, but the seas calmed to 3.5 feet or less, and we safely made it home. At 3 feet, we will travel anywhere between 7 and 15 mph, which is entirely dependant on the conditions relative to tide and wind. At 2 feet, we can usually go 10 to perhaps 20 mph, also dependant upon conditions. At 1 foot or less, we set optimum throttle settings to achieve 3500 rpm, which gives us anywhere between 18 and 24 mph. Obviously, if the speed dips to 18 mph, for example, I'll have to readjust throttle settings to get a more efficient rpm rate. Occassionally, I'll go 30 mph for a few minutes to get home quickly, but as you would expect, efficiency drops significantly. I never take it past 30 mph; in my opinion, that is too fast for a planing boat of our size. At 35 mph max speed, it feels like we are traveling on ice.

l don't want people to get the false impression that I'm overly focused on economy. On the contrary, I find it critical to know how many miles per gallon we experience in our area, and in varied conditions, so that we can determine a realistic range for our boat, which we set at 270 miles (assuming 60 gallons starting out.)

Rich

Rich
 
Rich,

Thank you for posting your real world economy/performance numbers for your beautiful Marinaut.

I had the privilege of viewing your boat during it's construction phase and I can tell you that the Les Lampman Marinauts are built better than any other of the C-Dory family of boats that I have examined. The hulls are expertly crafted and the assembly work at EQ is completed as if each boat is to be Les's own personal craft.

I believe that your performance numbers are accurate and represent a documented average for a well equipped and moderately weighted Marinaut. My wife and I had the pleasure of sea trialing a Marinaut last September and we came away amazed at how well the boat handled and the unbelievable economy numbers posted on the Evinrude's gauge.

In short, the Marinaut performs much better than our 1992 22 Cruiser but then we only paid $29,000 for that boat new. I'm excited about the Marinaut and embrace it's superior design and performance.
 
Thank you for your kind comments, Jerry. Our experience with boats pales in comparison to yours, but we are very pleased with our boat. You are particularly right-on about Les. He and Kathy are a throw back to better times when a handshake meant something and people delivered on their promises. We have had the boat for one year now, and have spent over 31 nights on her. It's going to be hard putting her away for the season on October 15th; our season is too short in New England.

Rich
 
Will-C":3gbo1yvw said:
I guess that just about wraps it up. The Marinault 215 and the Honda BF 115 are the best boat and motor ever built. AMEN
D.D.

Dave-

Amen! :wink

But keep the helmet on, more incoming! :smileo

I guess someone's just in love with their new boat. no?:smilep

OTOH: Maybe it time for a separate Marinaut site? :lol:

Much Easier: Just read the posts selectively! :smiled

At least it's not political or religious disagreement! :amgry

Joe. :teeth :thup
 
My comment was misunderstood. I was simply synthesizing general info on many different boats and motor configurations in the general class as the M and CD. I was only indicating that physics ultimately rules and probably puts all boats of the M and CD class pretty much neck and neck for fuel IF you could absolutely duplicate conditions, which of course, you can't. I made my comment as a GENERAL observation without the intent of putting down or boosting up any manufacturer.

I'm simply not interested enough in making the detailed and painstaking effort to figure out what MY MPG is as it will only be good on that day with that load with that power setting and that trim and at that density altitude and those water and current conditions. So, if I am within 25% of accurate for trip planning, I'll carry at least a third more fuel than that 25% uncertainty predicts. End of worrying about MPG.

I do like fuel flow though as a means of getting the best I can under those conditions of power setting, density altitude, load and water conditions.

I can say in general terms that the pleasure I get from my CD makes me very okay with my MPG. Which falls well within the 2.5 to 5 mpg others are getting depending on load and on or off plane. My MPG is probably going to be lower than most of the folks here because I hang out a 3500 to 7000 foot lakes most of the time, and on hot days at that. I'd rather be looking out at the water and the mountains and enjoying the movement over the water than fine tuning MPG, or arguing about it.
 
Fifteen months ago I asked DaNerd (aka DaNag) if he would set up an "All Marinauts, All the time" sub-forum. The reason I asked him to do so was because I was fairly certain that the Marinaut boats would be discussed and I thought it was better that the discussions occur in a separate sub-forum rather than in the general forum. Why? Because it's a lot easier to ignore a sub-forum than it is interspersed posts within a larger forum. Therefore those not interested could easily avoid having to sift through posts about other than C-Dory branded boats if that is their desire.

If you care to look at the my join date over there to the left you'll see that I joined 30 Oct 2003, even before EQ became a C-Dory dealer (in fact I was also on the C-Dog site prior to shipping over). So you know I've long supported C-Dory boats and their owners. I've made a lot of great friends because of it. The point being that I did not ask DaNerd for a sub-forum so I could overwhelm the C-Brat site and the focus on C-Dory boats but rather because of the shared kinship between the C-Dory and Marinaut and because with one boat in the field (and four in production at this point) there's hardly enough critical mass to sustain a separate owners site.

I'm rather taken aback at the sniping going on in this thread. Rich has taken the time to report what he's observing with his boat so that others interested in the M215 will have some from-the-field information rather than relying on some slick sales dude spouting off. I can tell you that Rich's background lends itself to this sort of endeavor and he's just a bit on the picky side about data. I can also tell you that the Honda BF115 is a NMEA 2000 engine and the fuel burn is being reported right from the ECU to the Raymarine nav system for display at the helm. Speed is obviously coming from the GPS function of the nav system. Without resorting to measured fuel and radar guns I don't know how you get any better than that in real world (everyday) usage. The numbers that Rich is reporting are not the same as a light boat tested by a factory and then hyped up in their literature.

Rich is also not reporting his numbers in an effort to make the M215 "look better" than a C-Dory 22. After all this is the Marinaut sub-forum so the information is being posted in an appropriate place and we're being hosted by a site dedicated to C-Dory boats; it would be in poor taste to purposely denigrate the very boats that make having this sub-forum possible. I've asked all that post about the Marinaut to "stick to the facts m'am". The M215 is what it is, good or bad. There's no reason to hype it or trash it, it can stand on its own (or die for that matter) if honest and factual information is presented.

I can tell you why the M215 typically does better than the average CD22 and it shouldn't be surprising that it does given the years available to the designer to improve on an iconic design. In short, the CD22 as we know it today is stern heavy and oft times by a long way compared to optimum. It's a result of an earlier design having to suffer the aging process at a time when motive power is changing drastically. There is no way to take a hull design that was intended to carry about 375 pounds on the transom along with 36 gallons of fuel and a couple of (relatively) lightweight all purpose batteries and have it perform at its best with 500+ pounds on the transom along with 46 to 50 gallons of fuel and heavier batteries (often an AGM group 24 and 31). That would defy well known yacht design parameters along with physics. The typical modern CD22 is out of balance and the fuel economy suffers because of it. That doesn't lessen the fun one can have with the CD22 and it doesn't negate all of its good attributes, it does mean that it doesn't do as well as it could with a lot less weight in the tail end. I've personally run a CD22 with nothing but an E-TEC 90 on the transom and it performed as originally intended. I've no doubt that a CD22 powered with a lightweight engine (less than 400 pounds on the transom with a kicker) would do every bit as well as the M215. You can't take a hobbled CD22 and expect it to perform better than a much newer design that's specifically intended for heavier modern engines and that has the advantage of another 25+ years of experience behind it. If your 2012 vehicle can't boast being better than a 1987 version it's time for the design team to hang it up and go home.

The M215 was designed specifically for heavier 4-stroke outboards and the weight of the fuel was moved out of the transom (where it has the most affect on balance) and put forward to each side in saddle tanks. The balance, the waterline, and the shape of the M215 is completely different than a CD22 and for good reason given modern power plants and loads.

With 5 adults aboard, on a boat loaded with gear for a few days at a time cruising, and with full water and fuel aboard the Marinaut planes at 9 knots. It's totally balanced and able to take advantage of that happy state of affairs. When I did the testing for the Honda website (the Marinaut is on there under the BF115 section in their performance reports) time to plane was usually less than 3 seconds (and that was with a Honda observer on board and he was running the stop watch).

There are two other factors at play: the specific engine that Rich is running and the weight of the M215. Honda detuned the BF135/150 to come up with the BF115. It's a large displacement engine (for its horsepower) and because of that Honda put the peak torque of the engine down at 3,500 rpm. It also has the best specific fuel consumption of all the larger Honda engines (that's the amount of fuel required to produce one horsepower). The M215 hull can really take advantage of that and I'll be the first to admit that this is a totally serendipitous happening (meaning we didn't design for it, it just happened). The M215 runs very nicely at 3,500 rpm (18 to 19 knots), right where the engine is in a total "sweet spot". At that speed fuel burn is just over 4 GPH.

The M215 is light. All nine fiberglass pieces that make up the boat come to 1225 pounds. We add about 500 pounds in completing the boat to the same stage as a CD22 leaving the factory (fuel and water tanks in, rails on, interior in, windows in, etc...but no engine or customer rigging). Typically a completed M215 is about 300 pounds lighter than a C-Dory 22 completed to the same stage. That's equivalent to a couple of folks on board (well, at least a couple of light ones).

I still like the C-Dory 22 and I totally get why someone might choose it over a Marinaut 215. They're different boats (in spite of their shared heritage) and I would fully expect that one or the other would or could appeal to folks when choosing a boat for their own needs. My best friend of many years has a 1994 CD22 that he bought new and still has; I spent a lot of time on that boat (and still do) long before I had anything to do with C-Dory boats on a professional level. There's also another C-Dory 22 in my life right now that I plan to spend plenty of time aboard and fully enjoy. So if anyone thinks that I'm going to stand over here in the Marinaut section and throw rocks at the C-Dory section they're mistaken, and sadly so.

So quit picking on my doggone Marinaut! It's a boat, it floats, it's for fun, and it's just another choice of many. If offers another choice to folks looking for a trailerable "pocket cruiser" though it's by no means the "only choice" or even the "best choice" depending on what one wants.

And quit picking on Rich, we're supposed to be above that garbage here and I expect folks to comment and conduct themselves in that spirit. Snide remarks can be taken to the "that's life" section if you feel an overwhelming need to carp. Honest questions are of course encouraged and welcome but let's please leave it at questions and useful intercourse and leave the (semi) rude comments for other forums and places where it's more common and expected.

If you really think the numbers are BS hop a flight or drive to Connecticut and take a trip with Rich and Betty on the Betty Ann and decide for yourself whether or not the data is correct and the observations valid. Soon we'll have several other M215s on the water so if you're not within striking distance of Connecticut there should be a boat a bit closer.

I'm buried up to my eyeballs in production at the moment so I am sorry that I'm not here more often and participating (I hate that part of being busy). I'm sorry if some of this sounds like a rant but I have to speak the truth and say that I'm upset and angry about some of the crap being dished out in this thread for no other reason than someone has a keyboard in front of them.
 
I did not post detailed information in the C-Dory forum, but rather in the Marinaut forum. When I first looked at C-Dorys several years ago, the wealth of information on this site was instrumental in my selecting a CD 16 Cruiser as my first boat. Everything I needed to know to make a decision: handling, economy, value, quality -- it was all there. And when it was time to sell my CD 16, my contributions along with this chorus of information helped me as it has helped those members on this site whom have sold their boats. You should be proud of the respect you have earned from outside the C-Dory community.

There is a dearth of information, at least relatively speaking, about the Marinaut. I have taken great pains to fill in those gaps to help others make informed decisions, and throughout this process, have given C-Dorys their just due. That's why this information was posted in the Marinaut forum. And when the proud owner of Hull #2, #3 and etc. come along, they too can add information to the Marinaut forum. Some of you may not be interested in such detailed information; that's O.K. There is room on this site for both boats.

Finally, the Marinaut belongs on this website. It's designer is Ben Toland, and many of you have enjoyed the fruits of his labor manifested in C-Dorys. The very capable Dave Thompson's ideas gleaned from year's of experience with C-Dorys and learning about so many creative solutions from its owners was the impetus for developing saddle fuel tanks and an open berth on the Marinaut. And many of you truly appreciate the work that Les and Kathy have done for you, as well as contributions made to this site. We are all one family.

Thanks for listening,

rich
 
I have around 1100 hours on my twin honda 45 set up and with a light load (2-3 people, full gas, full water, and a good assortment of fishing stuff) and it takes 17 gallons to go on my 68 mile trip to my halibut spot. I have made the run for around a decade (weather permitting of course) and this burn rate has been extremely consistent. 4mpg isn't too bad in my book.....And I have gotten it for so long, I think it is reasonable to think that next year, that is what I am going to get again......

With a heavier load (4 people and their catch) I have to swith tanks at the Cape (with some gas left as I don't want to run out on step with all the boat traffic) and the 2nd tank typically takes 6 gallons at the dock. The first tank almost always has 2 gallons left in it before the switch (18 gallon tank). This puts the fuel economy at 3 mpg.

So, I am sure you are wondering what speed that is. Well it is everything from 10 mph all the way to 24 with the most typical speed being 13-18. mph. Most of the cruise time has been from 13-18 mph.

I personally think it is going to pretty hard to find much variation in the economy of the boats with similar power plants and similar loads going a similar speed. The design just isn't that different to warrant a significant difference. Something? Well sure....But I bet it is less than 5%, which certainly isn't enough to get upset about. Or, even sing praises about.
 
A couple more observations on CD22 performance/fuel economy...

I tend to use a lot of trim tab deployment to keep the bow down. Normally 65-75% when the boat is loaded heavily (heavy stuff inevitably ends up in the cockpit). The engine (with SST hydrofoil) is also typically trimmed to aggressively keep the bow down.

The BF90D runs at fairly high RPMs to keep the boat on plane. Loaded heavily and spinning a 13.75 x 13 aluminum prop, 4400 RPM equates to only 13-13.5 knots. 4800 RPM brings the speed up to around 16 knots and at 6200 RPM I can make 24 knots. With lighter loads I run a 13.5 x 15 aluminum prop and see higher speeds for a given RPM, but fuel economy seems pretty similar. Bottom line: the engine on my C-Dory is working much harder than the BF115 on Rich's Marinaut.
 
T.R. - 4 mpg with a light load is fantastic, but it looks like there is a 15 percent difference, which is explained in Les' comments. Regardless, there are few boats the size of the C-Dory that can get such great mileage, and to do so safely at that.

Retriever -- My trim tabs are usually set at 20 or 30 percent in following seas, and 40 to 90 percent when bucking the current so as to keep the bow down. Obviously, the degree of trim is also governed by speed travelled. Engine trim is always down. It does not appear that the degree of trim applied necessarily affects fuel economy appreciably. The Marinaut may be a well balanced boat, but we have a lot of weight in the stern. We have the 500 lbs. Honda Bf115, 120 lbs. kicker and offshore bracket, two batteries, and tucked under the splash well: 24 pounds of water in plastic bottles, and a large porta-potti at approximately 40 pounds. I often wonder how much better she would improve with respect to fuel economy if we did not have that kicker, but I would feel very vulnerable without it. Lastly, when we are bucking a significant tide and wind, we extend the trim tabs down and travel around 15 mph (as stated in a previous post, some times even slower then that, which is dependant on wave height.) We could go much faster, but we find that this is an excellent speed for smooth traveling in those conditions.

Thanks,

Rich
 
Les, Rich, and all-

Sorry to get you so upset!

I've very much enjoyed your, Dave Thompson's, and other's posts about the development of the new Maurinaut!

It's just that the daily hammering over the fuel mileage figures has become a bit much (IMHO), and I'm ready and prefer to read about another feature of the new boat, instead.

Sorry, again, and Good Luck with your project!

Joe. :teeth :thup
 
I actually find it really funny that we are talking MPGs and boats in the same sentence. Heck, even my old, but well maintained, 351 powered ford bronco gets around 14 mpg - way better than either boat. And goes ways faster......Of course, it doesn't go well in the water......LOL.....
 
Me too. I came from sail and when a friend found out I was getting my first outboard boat a C dory 19 he told me to be prepared for 2 1/2 mpg. I thought he was nuts. So I am thrilled to get 3-31/2. Powerboats are always going uphill so I really appreciate the detail in Rich's post. As I sort of close my eyes at the pump , fill and then go cruising. When I get low on gas, I get more. Just like Forrest Gump would do. It costs what it costs and that's ok. So I have no real idea on exact numbers on Kerri On. I do know where she's taken me so far, and it's worth the money. thanks for the posts Rich. George
 
Joe, it's quite O.K., I have a thick skin. I agree with you about too much talk about mpg. I just made a simple posting to update people, and then get questioned on the results. So I was forced into a position to defend those figures, and ended up killing a dead horse. Unfortunately, even my response was redundant after Les' response; apparently our posts crossed in the mail.

To the writer with the SUV stating that gas usage is a fact of life for boats, that's true, but I had a choice when buying a boat, and chose the most efficient boat for our needs I could. Any time a person can save money, why not take advantage of it?

As for why I will continue to track precisely fuel usage, it provides a way to plan how much fuel We have remaining in our tank before gassing up, without having to rely on the fuel gauge. For example, if we travel 90 miles, we can assume 20 gallons of fuel had been consumed. Thus far, we have been dead on.

George,
I appreciate your comments. Thank you.

Rich
 
Rich,

I don't you need to defend your fuel numbers. They seem realistic enough. Out of the open Gulf of Alaska with currents and the winds, I have to have had a number of trips with incredibly similar fuel burn results to what you have recorded. My best economy has always been in PWS - not in the open gulf where my halibut spots are. My very best economy ever was on a Lake Roosevelt- no currents and nearly no wind. Of course it was.

However, stating that one boat is more efficient than the other, while simple to do, is actually very complex to measure accurately. In fact, I am just not going there as I cannot provide a large enough sample of either boats actual mileage in a number of conditions. The best is ball park. Your boat may indeed attain better economy, and I am certain your new boat is putting up better number than your old one. However, assuming it is better soley because of the design, when every other factor hasn't been analyzed completely, or even duplicated, is just one of a number of possibilities.

Of course, you know that and so does everybody else. And, I put the referrence to the old bronco in there as a joke as one of the least efficient vehicles on the road literally kicks both boats' proverbial butts when it comes to MPGs. It wasn't meant to anger you and I am sorry it did.

I know you are really enjoying the new boat - who wouldn't? The new Marinaut is beautiful. If I were in the market for a new boat of this size, it is a very good boat for sure and definately deserves a spot near the top of the list.
 
The M215 was designed specifically for heavier 4-stroke outboards and the weight of the fuel was moved out of the transom (where it has the most affect on balance) and put forward to each side in saddle tanks. The balance, the waterline, and the shape of the M215 is completely different than a CD22 and for good reason given modern power plants and loads.

Why did you folks not tell me there was a fight on? I all most missed out :wink:

I got to test drive the above mentioned boat and it runs great. I did not run any fuel numbers but I have no doubt about the numbers given. I think that the quote above seems to really answer the question as to why. Its a completely different hull. You can tell as soon as you push the power forward. It climbs out of the hole flatter and runs at a flatter angle ( not much) then my 22 did. It turns different, it handles different. Just a great preforming boat. I would not buy one as its too small for me and susan now. I will be looking forward to the 25 or 26 if it gets built.

The same argument was ongoing when the venture 23 was first on the marker, a great hull design. It was a step forward in design then the cdory 22 and by the same guy. The marinaut is a another step beyond that in design. What most people forget or do not know, because they have never SEEN one in person, is that the stern of the newer designs are very different then the cd22. All the cd22 and 25 and even my 27 get narrower at the stern. This is the biggest difference to me and I think the reason the newer designs get better fuel economy. I dont have any line drawings in front of me but I am willing to beat that the total square ft area difference is around 3 to 5 ft. Thats a extra 4 ft of lift area. Combined that to the balance issues that Les detailed and you have a more efficient hull.

Its not rocket science and more importantly its not personal. One boater getting better fuel numbers then you takes nothing away from your boat and your love of using it. Its really silly to argue about. Its like saying that because some one else has more money that my money is less or not enough??? justs nuts. or that just because someone else's idea of who to marry is different then mine that my marriage is effected somehow. Just crazy talk.

I love my boat and I love using it. I have friends that have better fishing boats and friends that have better cruising boats. Guess what? I still love to cruise and fish out of my boat and catch more fish then some of my friends with better boats. wise man said " if you cant be with the one you love, love the one your with" He was not or is no longer married but that's a different story. We really need a emotions symbol for stirring :twisted: [/url]
 
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