What's your cruising speed.

Marin,

After making the same point in a series of 3 or 4 posts in addition to countless other threads over the years, does, in fact, appear to me and others as an attempt to shut down the conversation. You've made your point....now move on. If you don't think it's a relevant conversation to have, then don't have it. But you do yourself a great disservice to make up statistics then argue against them. See Straw Man link above.

I have never begrudged a single dollar spent boating and I've been doing it all my life. . The intrinsic rewards are so great.....Relaxation, Peace of mind, mental health, enjoying the environment, spending time with spouse and friends etc cannot really be quantified in Dollars/hour spent boating. Fuel costs mean nothing in this scenario....And I spent most of my life sailing where fuel costs were never an issue. Sure it's more now with a powerboat, but, Honestly, it just doesn't matter to me.. For those of you that count the pennies, i feel sorry for you...Just do it, just enjoy it. If you can't afford it or justify it, my advice is to find another outlet.

manyboats said:

Who is this guy w 117 posts that obviously thinks he can tell the rest of us what to do.

His "move on" post very out of place.

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I don't see it the same, manyboats. Everyone here has a voice, especially the newer members. It's easy for us old timers to think of this as our round table, but this site is here for everyone to participate and feel welcome. I read Liberty2015's "let's move on" post to mean let's continue the conversation and skip this silly smack down by Marin. In that spirit, I wholeheartedly agree.

manyboats said:

Who is this guy w 117 posts that obviously thinks he can tell the rest of us what to do.

His "move on" post very out of place.

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Eric-- I don't think the number of posts is very significant. There are people here with 3,000 posts or 6,800 or more who are always trying to do the same thing. Disagreement is one thing. Saying or implying that someone who disagrees should not be posting their position is something else and I don't believe is in keeping with the intent John Baker had when he created this forum back in 2007.

The subject of this thread is fuel consumption. To that end I believe anyone can say anything they want that relates to that topic as long as it adheres to the forum guidelines for posts.

Guys and gals!


Instead of implying: "Let's Move On" I would like to say: Let's Continue to Get-It-On!!


Regarding all things having to do with marine items/circumstances... that may/could come to light.


TF is a pretty darn cool, informative, and fun marine forum. Every person has idiosyncrasies... be they persons with 13,239 posts or with 117 posts or less... sooo, I repeat, Let's Continue to Get-It-On!!


Happy Marine-Chat Daze! - Art

Thought I would Post this for what it is worth, really only means a lot to me, as we know each vessel has different circumstances. Earlier this year we did a 3 1/2 month round cruise from Sydney Australia ,down and around Tasmania and back. These are the stats we recorded.

We have twin 3406 Cats 540 hp each , we weigh 36 tonnes , carry 6,500 litres of fuel, 1,600 litres of fuel,Cruise at 9 knots at 1150 rpm with both engines running. Max rpm for the vessel is just on 2000 rpm.
-----------------------------------------------------------------------------
Below is an Email to a fellow friend who has a Marlow 57 on our dock.

Hi Bruce

You asked me on Sunday how much fuel I had used and I said just under 10,000 litres, this was not quite true, I was close but not correct.

Yesterday I sat down with the fairly comprehensive log for the trip and collated the important Stats for Liberty , and they are as follows

Total of Nautical miles covered. 2,469 Sydney to Sydney.

Total Fuel consumed 10,428 litres

Total Hours run. 273 hours

Average speed. 9.04 knots

Average litres per hour. 38.19 litres/ hr combined.

Mechanical issues

1 x port Starter motor

Leak in the port mechanical raw water pump which happened on the trip home --- resulted in damage to alternator, now not charging. The pump will come off next week for repairs.

Port drip less shaft seal was overheating near Eden on way home made phone call to mechanic, also reviewed the details of the seal on the web( handy whilst at sea) followed instructions from mechanic and then there was no issue , appeared to be an air lock /blockage in the coolant line to the seal.

Have got a couple of oil leaks , which we will attack whilst servicing the engines in the coming weeks, might need a new gasket here or there ?

Lazerette bilge pump failed ( old age caught up with it) on way to Hobart, replaced it before we started circumnavigation .

So all in all the prep we did for the trip paid off, and we got off lightly .

---------------------------------------------------------------------------------------

Thought you Guy's might be interested in this information .

If I was to cruise at possible a knot faster at 10 knots my fuel consumption would be an extra 1,400 litres at 1.36 / litre = $1,904.00 Aus or US $ 2,475.20 so on a cruise like this it is important to to get the boats sweet spot where you want it.

Our fuel in Australia is expensive compared to the States, at 1.36 a litre that is 5.14 US /Gal. We feel this is quite reasonable at present, we have been paying up to 1.60/litre on the water or 6.04 us / gal. I have seen references to 3.00 us /gal this would be 79 cents a litres , this would be like going back to the early 90's in Australia !!!

Cheers Chris D Liberty Australia

Second that, Art.

Thanks Liberty2015, shows more than just us poor guys or very few boaters (as there are boaters outside of the US West coast) worry about fuel costs.

Oh and not to piss you off too bad...just looked up a possible fuel stop for next month's trip and they are $1.93 US a gallon.

Liberty - TY for your comprehensive, interesting post #246 - Art

Marin, you posted your reply to me on this thread which all subscribed to the thread have seen, then deleted it yourself. In it, you claimed I would delete your post. I have not deleted any posts on this thread and have no intention of doing so. I will, however, continue to stand up for those who share a differing opinion from yours that you repeatedly attempt to discount and intimidate. I am not an administrator here and only volunteer as a moderator to pay back for the great info I receive here. I figured I owed it to the TF community and intend to continue to do so as long as the community values my contributions and volunteer efforts.

We strive to keep ALL lines of communication open here on TF. But we also recognize that the opinions stated over and over again in the same thread and over the years has been heard by all. There's really no need to continue to restate them ad nauseum. We get it....let's move on.

Trust me when I say that I get no pleasure from having to deal with the daily tasks of moderation. It's a thankless, behind-the-scenes job that takes much time over most days. There has been no moderation of this thread...mine is merely the opinion of one with whom you disagree. I am posting here as a member and not as a mod, although I understand that my posts can be seen as mod-in-nature. When the day comes that I cannot post as a member here, then I will gladly stop my volunteer duties on my own.

In the meantime, we as a Site Team will continue to work around the clock to keep the lines of communication open and flowing. Got an opinion? State it. Once is normally enough. Others have a differing opinion? Listen or ignore at your choice, but let's not crush the voices of those with whom we disagree with ridicule or banter. It's not civil and it's not right.

By posting this reply, I am bending the rules of mods by discussing mod issues, but so be it. It needs to be stated for the subscribers to understand that we are there for them as a community. I have little doubt that this post will be deleted but stand by it, nonetheless.

Let the conversation continue in a civil and welcoming nature.

Liberty2015 said:

Thought I would Post this for what it is worth, really only means a lot to me, as we know each vessel has different circumstances. Earlier this year we did a 3 1/2 month round cruise from Sydney Australia ,down and around Tasmania and back. These are the stats we recorded.

We have twin 3406 Cats 540 hp each , we weigh 36 tonnes , carry 6,500 litres of fuel, 1,600 litres of fuel,Cruise at 9 knots at 1150 rpm with both engines running. Max rpm for the vessel is just on 2000 rpm.
-----------------------------------------------------------------------------
Below is an Email to a fellow friend who has a Marlow 57 on our dock.

Hi Bruce

You asked me on Sunday how much fuel I had used and I said just under 10,000 litres, this was not quite true, I was close but not correct.

Yesterday I sat down with the fairly comprehensive log for the trip and collated the important Stats for Liberty , and they are as follows

Total of Nautical miles covered. 2,469 Sydney to Sydney.

Total Fuel consumed 10,428 litres

Total Hours run. 273 hours

Average speed. 9.04 knots

Average litres per hour. 38.19 litres/ hr combined.

Mechanical issues

1 x port Starter motor

Leak in the port mechanical raw water pump which happened on the trip home --- resulted in damage to alternator, now not charging. The pump will come off next week for repairs.

Port drip less shaft seal was overheating near Eden on way home made phone call to mechanic, also reviewed the details of the seal on the web( handy whilst at sea) followed instructions from mechanic and then there was no issue , appeared to be an air lock /blockage in the coolant line to the seal.

Have got a couple of oil leaks , which we will attack whilst servicing the engines in the coming weeks, might need a new gasket here or there ?

Lazerette bilge pump failed ( old age caught up with it) on way to Hobart, replaced it before we started circumnavigation .

So all in all the prep we did for the trip paid off, and we got off lightly .

---------------------------------------------------------------------------------------

Thought you Guy's might be interested in this information .

If I was to cruise at possible a knot faster at 10 knots my fuel consumption would be an extra 1,400 litres at 1.36 / litre = $1,904.00 Aus or US $ 2,475.20 so on a cruise like this it is important to to get the boats sweet spot where you want it.

Our fuel in Australia is expensive compared to the States, at 1.36 a litre that is 5.14 US /Gal. We feel this is quite reasonable at present, we have been paying up to 1.60/litre on the water or 6.04 us / gal. I have seen references to 3.00 us /gal this would be 79 cents a litres , this would be like going back to the early 90's in Australia !!!

Cheers Chris D Liberty Australia

Click to expand...

Great point of reference, Liberty! Thanks!

FlyWright said:

Marin, you posted your reply to me on this thread which all subscribed to the thread have seen, then deleted it yourself. In it, you claimed I would delete your post. I have not deleted any posts on this thread and have no intention of doing so.

Click to expand...

FWIW I moved the post from here to Off Topic a few minutes after I posted it because it became obvious to me that I was violating the forum's own guidelines by reacting to a post that also had nothing to do with the thread's topic of fuel consumption. I figured you or some other administration member would rightly delete it for the same reason I did. I was not trying to make it look like you deleted the post. If participants in this thread got that impression I apologize. That was not my intent.

See what happens when you color outside the lines....

psneeld said:

see what happens when you color outside the lines....:d

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lol...

psneeld said:

Thanks Liberty2015, shows more than just us poor guys or very few boaters (as there are boaters outside of the US West coast) worry about fuel costs.

Oh and not to piss you off too bad...just looked up a possible fuel stop for next month's trip and they are $1.93 US a gallon.

Click to expand...

that's insane, its only 51 cents a litre , a third of what we pay here on average. Make the most of it, and enjoy your time on the water.

Cheers Chris D Liberty Australai

Marin said:

No, you didn't miss anything. Once again I assumed a higher degree of perception than I should of. The "10th of gph" comment was something often used in communications to make a point. It's called "exaggeration." ...

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Yes, but I call it "hyperbole." Use it myself. I usually take things literally, but have to restrain myself.

psneeld said:

See what happens when you color outside the lines....

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Oh shut up Bozo

Marin said:

No, you didn't miss anything. Once again I assumed a higher degree of perception than I should of. The "10th of gph" comment was something often used in communications to make a point. It's called "exaggeration." I'll try to think of a simple, more literal phrase than "wrapped around the axle" and get back to you.

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Now now Marin...don't get your wetsuit in a knot..He he 'knot'...get it
Oh, and by the way it's 'should have', not should of...just sayin'...

However, having had my dig, I must agree some folk do seem a bit more concerned with fuel economy than most. Can't say I worry about it. It is the cheapest part of our kinda boating, for sure, whether going fast (for my boat), or slow...

CPseudonym said:

Oh shut up Bozo

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Youse talk'in to me wiseguy?

Marin's not upset.
If he was we'd know it.
My i-pad's not even smok'in.

Simple answer(s) to the question:
My boat gets more speed than your boat.
My boat gets more MPG than your boat.
My boat is more (handsome, cute, pretty, neat, etc etc) than yours.
My boat is roomier than yours.
My boat is beamier than yours.
My boat is longer, shorter, fatter, wider, narrower than yours.
My boat has more head, interior, knee, engine room than yours.
My boat costs less, more or the same as yours.


Those are the correct answers to these and many more questions that are burning through our minds as we contemplate our purchase......

The personal interpretation of any of this info is subject to the readers ability to extrapolate the info, and use it (in)correctly to make their own (un)informed judgement.

Sorry to disrupt the entertainment with some of what the OP was asking......

I normally cruise between 8 - 9 kn. Seems reasonable speed, fuel consumption etc. I really wanted an economical (2 nmpg) 10 kn cruise, but went for more comfort instead. That's another story, but there is some kind of rationale for my cruise speed.

Below is a graph of my sea trial data in a somewhat unusual format: gallons used versus time taken for an arbitrary 100 nm trip. The data points are different rpm and speeds. Fuel use is total for both engines as determined by the John Deere fuel flow instrumentation, which is reputedly very accurate unless at quite low rpm.

The trendline was a fit by excel. Coincidentally, I always operate in the area below the trendline. Normally close to the middle of that area: 8.5 kn plus or minus a bit. If I had a good equation to fit the data and could remember any calculus I'm thinking that point is the maximum rate of change point, likely to be an optimum of fuel use and time taken. I must have figured that out by gut seeing as I cant remember how to do the math!

Trying to go faster than 'fast cruise' just makes a big wake with little time benefit. Going slower than 'slow cruise', apart from being altogether just too slow, doesn't save enough fuel to bother....

Insequent said:

Sorry to disrupt the entertainment with some of what the OP was asking......

I normally cruise between 8 - 9 kn. Seems reasonable speed, fuel consumption etc. I really wanted an economical (2 nmpg) 10 kn cruise, but went for more comfort instead. That's another story, but there is some kind of rationale for my cruise speed.

Below is a graph of my sea trial data in a somewhat unusual format: gallons used versus time taken for an arbitrary 100 nm trip. The data points are different rpm and speeds. Fuel use is total for both engines as determined by the John Deere fuel flow instrumentation, which is reputedly very accurate unless at quite low rpm.

The trendline was a fit by excel. Coincidentally, I always operate in the area below the trendline. Normally close to the middle of that area: 8.5 kn plus or minus a bit. If I had a good equation to fit the data and could remember any calculus I'm thinking that point is the maximum rate of change point, likely to be an optimum of fuel use and time taken. I must have figured that out by gut seeing as I cant remember how to do the math!

Trying to go faster than 'fast cruise' just makes a big wake with little time benefit. Going slower than 'slow cruise', apart from being altogether just too slow, doesn't save enough fuel to bother....

Click to expand...

Brian, that's a great way to graph fuel consumption! I like the idea of an upper limit beyond which fuel consumption goes stupid and a lower point beyond which slower offers no appreciable savings.


Ted

Yes, that was good Brian. Even I could understand it. I guess I'm not doing too badly to get 1nmph per litre...but at about 7.5 kn.

Insequent said:

Sorry to disrupt the entertainment with some of what the OP was asking......

I normally cruise between 8 - 9 kn. Seems reasonable speed, fuel consumption etc. I really wanted an economical (2 nmpg) 10 kn cruise, but went for more comfort instead. That's another story, but there is some kind of rationale for my cruise speed.

Below is a graph of my sea trial data in a somewhat unusual format: gallons used versus time taken for an arbitrary 100 nm trip. The data points are different rpm and speeds. Fuel use is total for both engines as determined by the John Deere fuel flow instrumentation, which is reputedly very accurate unless at quite low rpm.

The trendline was a fit by excel. Coincidentally, I always operate in the area below the trendline. Normally close to the middle of that area: 8.5 kn plus or minus a bit. If I had a good equation to fit the data and could remember any calculus I'm thinking that point is the maximum rate of change point, likely to be an optimum of fuel use and time taken. I must have figured that out by gut seeing as I cant remember how to do the math!

Trying to go faster than 'fast cruise' just makes a big wake with little time benefit. Going slower than 'slow cruise', apart from being altogether just too slow, doesn't save enough fuel to bother....

Click to expand...

Actually, without actually charting it in that manner, we do often look at the day ahead in that manner. We had two legs at the start of our current trip. Miami to Key West 170 nm., so our goal was average 17 knots, 10 hours. However, the next leg was Key West to Naples, 214 nm. With the time in and out at 10 knots, we figured 20 knots on the majority of that leg. Then Naples to Ft. Myers Beach 50 nm. For that, leisurely pace allowing 4 hours was just fine. About half the gpnm.

I like the chart as it is for many considerations but we also often need to figure tides around here. Just a few weeks ago heading up the Hudson it was much better and almost the same fuel cost to place the rpms for 17 knots (in neutral seas) then running at what would have been 8 knots without tides.
Figuring your SOG and where you will be in a few hours and the new SOG will often lead you away from the standard calculations.

6 knts max speed 10knts. Reduction almost triples range. Since my boat is so damn slow , no point getting in a hurry. There are plenty of times I miss thespeed of past boats. That's why you need a fast small boat as well. Ideal would be a twenty foot aluminum with a good sized four stroke outboard.

I travel between 35 and 65 miles per hour going to/from the boat. That satisfies my need for speed. Makes me appreciate 6.3 knots on the water.

This last Tuesday had several episodes with tugs-with-barges heading directly toward me. Slow-going gave time to react. (Altered course; they did not.)

markpierce said:

I travel between 35 and 65 miles per hour going to/from the boat. That satisfies my need for speed. Makes me appreciate 6.3 knots on the water.

This last Tuesday had several episodes with tugs-with-barges heading directly toward me. Slow-going gave time to react. (Altered course; they did not.)

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Did they see yellow and target you?

Our GB 42 Europa idles at about 5.2 knots and will run all day at 15 knots. The optimum $/mile, which I believe is raw right measure, is at 9.3knts. Our plans use that speed but when running in waves, the better ride is usually around 13 knots.