What's your cruising speed.
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Nomad Willy
Guru
Speed is highly related but this is about the cost of fuel. There's been many hundreds of posts about fuel burn down through the years. Many threads. People here obviously have the boats they want but can't afford. And the answer is to buy smaller boats. All our lives we've beed upsizing not downsizing so it's hard to do.
Many or perhaps even most of us have from youth (a long time ago) have had a play world centered around mechanized toys dominated by those that burn oil in one form or another. How many engines do you own? Count them. Most will be shocked to realize how many there are. BandB was right. One should boat according to the conditions and the conditions now are high fuel costs and too many people on the water. Smaller boats are the way to go. Or even finding something else to do like bicycleing that dosn't burn much fuel. Not in our natural catergory of likes as we'd rather ride a big motorcycle or truck that makes lots of noise. It's making a bold statement saying I'm not going to go quietly ... as in protest. It's our way of life (at least playing and many for working too) but I hear a lot more whining than stories about adapting to present and future assumed to be conditions. Actually the abundance of big pickups and motorcycles that make a lot of noise are directly related to this. Little pickups and motorcycles were very popular a short time ago ... but now almost extinct. I'll bet very soon little pickups and motorcycles will become popular again. Styled in of course in a different way to achieve the necessary vougeness.
Many or perhaps even most of us have from youth (a long time ago) have had a play world centered around mechanized toys dominated by those that burn oil in one form or another. How many engines do you own? Count them. Most will be shocked to realize how many there are. BandB was right. One should boat according to the conditions and the conditions now are high fuel costs and too many people on the water. Smaller boats are the way to go. Or even finding something else to do like bicycleing that dosn't burn much fuel. Not in our natural catergory of likes as we'd rather ride a big motorcycle or truck that makes lots of noise. It's making a bold statement saying I'm not going to go quietly ... as in protest. It's our way of life (at least playing and many for working too) but I hear a lot more whining than stories about adapting to present and future assumed to be conditions. Actually the abundance of big pickups and motorcycles that make a lot of noise are directly related to this. Little pickups and motorcycles were very popular a short time ago ... but now almost extinct. I'll bet very soon little pickups and motorcycles will become popular again. Styled in of course in a different way to achieve the necessary vougeness.
tpbrady
Guru
For us it has never been so much the money, but being able to cover the distance between fuel stops. I started with a 22ft C-Dory and had some trips of multiple days covering 220 miles with 50 gals of gas. At that point it was a trade off between speed and fuel but the C-Dory did pretty well at 15 knots and toward the end of the trip after burning off fuel and reducing the amount of water, booze, food, etc it got a lot better. Today fuel is not so much an issue since the Nordic can make just about any run in SE AK at max sustained cruise 11 knots and have a little left over. However I can operate at less than 1 nmpg or at 3+ nmpg (7.5 kts). In 300 miles that is a lot of money. Since we cover around 2000 miles over the boating season, the difference between 1 and 3 nmpg is a whole lot of money.
Tom
Tom
MYTraveler
Guru
In my experience, the bigger the boat, the less significant fuel costs become. If you can't afford the boat, scrimping on fuel burn won't make the difference.
The arguments one uses to try to support their own likes and dislikes. I sure don't get the impression there are a lot of people here who have boats they can't afford. Do you mean can't afford to run wot 100% of the time? Or is it prefer not to, prefer to save some money to use for other things. I do not agree all the discussions of fuel costs mean people can't afford it. I, like most, can afford many things I choose not to spend on.
Conditions are high fuel costs and too many people on the water? Fuel costs are at a historic low. As to people on the water, I don't know where you decided it was too many. Is that when you're not the only one? Is two company and three too many? All I've heard for years is the reduction in people actively boating. Go boat on any inland lake in the Southeast and you'll find out what too many people feels like and yet it's still down from ten years ago.
Now we get to the point you'll use any possible means to make even with statements such as above that smaller boats are the way to go. Or bicycles. Damn, I tried riding my bicycle across the water and we sunk. Pedal boats maybe?
I respect that you've found the type boat and boating you enjoy other than that there are too many of us on the water. You don't need to use contrived arguments to support it. Just say "I believe" or "I like" and that's all it takes. We have 9 people on board at the moment and will have three more guests tomorrow. We'll have 12 or 13 for Thanksgiving. Please don't say I need a smaller boat.
There are certain topics that are always popular. Fuel consumption gets discussed on road and water regardless of current prices. I honestly heard in passing someone ask the other day what fuel mileage a Rolls Royce gets. That's like the restaurant where if you have to ask you can't afford it. I had no idea, but I did look it up. A Phantom gets 19 hwy, 11 city, 14 overall.
Enjoy your boat, your style, your dislike of hp and love of economic. I admire your choices. I just don't share them.
Nomad Willy
Guru
Many truths Mr B,
I think you're right but I don't think you've explaned all this fuel burn talk away. you forgot about the running twins on one talk that's been going on almost forever and never seems to die. The obvious answer is a mix of 4-5 ussues.
Every boat has a target design speed (fairly narrow range) that the boat was meant to run at and few here seem to be doing that. Another reason that may draw quite a few is that a lot of trawler skippers view passagemakers to be the ultramate trawler. And a low burn rate is a very high priority w passagemakers. But trawlers are a quite different boat from them. So perhaps a lot of trawler skippers are just trying to imitate the passagemakers. When I first got into this I read every word of PMM and still have about 30 of those mags plus the book Voyaging Under Power. Haven't read either for years.
Also most of us had faster boats when we were younger and miss the speed. I do. not only getting places faster but the feel of a planing boat underneath w nice banked turns.
I think you're right but I don't think you've explaned all this fuel burn talk away. you forgot about the running twins on one talk that's been going on almost forever and never seems to die. The obvious answer is a mix of 4-5 ussues.
Every boat has a target design speed (fairly narrow range) that the boat was meant to run at and few here seem to be doing that. Another reason that may draw quite a few is that a lot of trawler skippers view passagemakers to be the ultramate trawler. And a low burn rate is a very high priority w passagemakers. But trawlers are a quite different boat from them. So perhaps a lot of trawler skippers are just trying to imitate the passagemakers. When I first got into this I read every word of PMM and still have about 30 of those mags plus the book Voyaging Under Power. Haven't read either for years.
Also most of us had faster boats when we were younger and miss the speed. I do. not only getting places faster but the feel of a planing boat underneath w nice banked turns.
The last time I got fuel, I saw a man in a new Mercedes pull up to the pumps, get out to pump gas, and then stop. He turned to me and said, "It's 2 cents cheaper down the road." He told me where. He seemed bothered I didn't stop pumping then. So everyone has their areas in which they become very cost conscious, just different for us all. You're right though about twins on one for whatever reason, not wanting to run the boat as it was designed. However, one thing you see here is a huge amount of semi-displacement and even planing boats being used as displacement because they were more affordable or had better layouts than boats designed for slower speeds.
However, most naval architects and most builders take the dual function into consideration now. A tremendous percentage of new boats are advertised with WOT, Cruise, and Economy Cruise. It's this is a nice cruise for this boat, a good point, typically cruise being around 70-80% load and this is a very comfortable slower speed to be more economical and increase your range. You see fast megayachts that have speed and range to cross oceans, but not both at the same time. I just pulled up a production 164' Westport to see how they put it. Max Speed: 24 kts. Cruise 20 kts. Range at 16 kts 2900 nm. Range at 12 kts 5200 nm. Grand Banks certainly doesn't expect their boats to primarily be run at cruise. Even Fleming quotes multiple "sweet spots". So designers do take into consideration the need for comfort at various speeds.
Nomad Willy
Guru
BandB,
I thought you're Mercedes guy was a joke at first. Can't relate to that as being anywhere near mainstream. But I've seen guys like that. Very expensive cars are common at the cut rate gas outlet ARCO. Perhaps they are scared to death of loosing their money.
Speaking of money, views on this speed and fuel burn issue will be all over the place on this forum as we are so diverse in what we have availible to spend on boats and other toys. I feel like a really poor Joe here but I'm a rich guy compared to Janice. And there are people here that I consider really well off that are average schmucks to many others.
I thought you're Mercedes guy was a joke at first. Can't relate to that as being anywhere near mainstream. But I've seen guys like that. Very expensive cars are common at the cut rate gas outlet ARCO. Perhaps they are scared to death of loosing their money.
Speaking of money, views on this speed and fuel burn issue will be all over the place on this forum as we are so diverse in what we have availible to spend on boats and other toys. I feel like a really poor Joe here but I'm a rich guy compared to Janice. And there are people here that I consider really well off that are average schmucks to many others.
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kulas44
Guru
I think Janice is richer than all of us put together.
Agreed!
But - Eric is pretty darn "rich" too... just makes comments sometimes that don't show just how "rich" he really is. Richness exists in many levels and forms. Both Janice and Eric are two of the forms!
Happy Personality Daze! - Art :lol:
Nomad Willy
Guru
Well I clicked three times ...
But it didn't happen.
But it didn't happen.
tallswede
Senior Member
Well, I for one appreciate the folks willing to give speed and fuel burn numbers. I gives me at least an idea what to expect from my new (to me) trawler as I learn how it performs. As one who has had planing hulls or sailboats it does me good to see how boats near mine in size/waterline perform. Personaly, I enjoy getting as much efficiency out of my cars, motorcycles and boats as I can even if they are not known to be very efficient. Getting 20+ mpg out of my 4x4 Jeep and big engine '79 TransAm is fun to me especially when I know what their performance on the other end of the spectrum is. I'm sure the same will be true for my 36' Prairie. Besides, when we take a long trip in the car or the boat, it's nice to know how far we can go on a tank of fuel. Like another has said, it can buy a nice meal at the end of the day.
Kevin
Kevin
I cruise at 400-500 off the top. *-450 gives me 27 knots on flat, slack water.
It's really tough being in the minority again.
Hi Moonstruck
I’m almost with you. Have been running a Cutwater 30cb for two years with a Volvo D6 435hp that cruises at 18-20 knots with a WOT OF 26 knots.But those days are behind us. Recently bought a Symbol 45 (loa 48 ft., beam 15 ft) that’s powered by a pair Yanmar 440s. Had both structural and mechanical surveys done as well as a sea trial with the surveyors aboard taking measurements and running tests. At wot of 3100 rpm she did 17 knots. At what the PO called fast cruise (2800rpm) she did 14 knots. Haven’t yet checked out slower cruise results, but expect to learn that and so much more on our maiden cruise with a professional captain from Baltimore to Port Everglades in two weeks.There we’ll load her on a boat carrier vessel for the trip through the Panama Canal up the west coast to Vancouver BC. From there it’s a short cruise to the Seattle area, just in time to begin our cruising season on the Salish Sea.
Even if we eventually cruise at 8-10 knots it’s comforting to know what we have in reserve.
Pete Meisinger
Guru
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- 36 Albin Aft Cabin
My 36 Albin (single F.L. 120) does about 7 Kn, One time a tailwind pushed me up to almost 9. Always get around 3 mpg. I tell my friends that to go any faster I would need to run it over a waterfall!
Woodland Hills
Guru
We have a 63’ lwl and I cruise at 1050 rpm at 10/11 gph total which typically gives 9.7/10 kts. We can get up on plane and run at 1950rpm and 18/21 kts depending on water depth, but then we burn in the low to mid 30gph range per side. We rarely do it, but it really helps smooth out the ride when it gets choppy.
Nomad Willy
Guru
So Hills you have a planing hull then.
Are you running Detriots?
Are you running Detriots?
Woodland Hills
Guru
Yes, an old Hatteras with two 12v71TIs @ 650hp each. 36”x36” wheels
That engine is rated for 3,300 rpm and if your reported wot rpm is accurate, ie phototach calibrated, then you are 300 rpm over propped. That engine definitely doesn't like to be over propped. Many reports of valves dropped at high loads.
Calibrate your tach if necessary and check again your wot rpms. If really 3,100 then take at least 2" of pitch off of the props to speed it up.
David
MurrayM
Guru
We have a Yanmar 4JH2 100hp engine (a tad too big methinks, put in by the PO) that we cruise ar 2700 rpm. This gives us between 6.5 to 7.5 knots depending on conditions, at a bit less than 1.5 gallons per hour.
The PO put in an extra 40 gallon fuel tank for a total of 140 gallons, so we have pretty good range.
David
Thanks for the info. The mechanical surveyor is going to be making a few adjustments before we head south. I’ll ask him to recheck the calibrations. If they remain the same I’ll follow up with it when we get her home. If we can speed her up all the better.
Regards Bob
North Baltic sea
Guru
Hi,
6,3kn-7nm/gal is my NT-37 eco cruise speed and if douple fuel consuptions i can run ~7,8 kn, hull speed is 8,2 - 3nm/gal...
And fast cruise speed 14-15kn 1,1 nm/gal
NBs
6,3kn-7nm/gal is my NT-37 eco cruise speed and if douple fuel consuptions i can run ~7,8 kn, hull speed is 8,2 - 3nm/gal...
And fast cruise speed 14-15kn 1,1 nm/gal
NBs
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Nice to see this old thread come back. Interesting info.
My panga was a planing boat but we cruised about 14 knots, inshore. When it got choppy out however my wife wouldn't be comfortable until we dropped to about 8 knots.
On my big boat 65ft, 55+ tons, I cruised 8.25 knots and never varied except to dock. Couldn't go any slower anyway since the Jimmies were at about 1300+ rpm and wouldn't want to slow them down any. I remember looking around for smaller injectors than the 55's so I could derate them a bit.
My panga was a planing boat but we cruised about 14 knots, inshore. When it got choppy out however my wife wouldn't be comfortable until we dropped to about 8 knots.
On my big boat 65ft, 55+ tons, I cruised 8.25 knots and never varied except to dock. Couldn't go any slower anyway since the Jimmies were at about 1300+ rpm and wouldn't want to slow them down any. I remember looking around for smaller injectors than the 55's so I could derate them a bit.
Commander Nomad
Veteran Member
8v71n Detroits pushing 70,000lb displacement, 7.5kt @ 1100rpm yields nearly 2nm/g. 1800 rpm is 12kt and a lot more fuel.
Woodland Hills
Guru
Are you saying that you idle at 1300+ rpm? My V12s idle at 650rpm and around 6.5kts, do 6-71s idle twice as fast?
Woodland Hills
Guru
We cruise at low rpm for economy, but periodically run them up for 1/2 hour or more to burn the moisture out of the oil. Folks say it’s to “burn out the carbon”, but that happens pretty quickly, it takes surprisingly long to get them fully up to temp and evaporate any condensation in the oil.
