Price Outlook?

Well, that's all I needed to read in the middle of a crap day at work /forums/images/graemlins/frown.gif

Hope you are having a great time. We are out in a couple of weeks and I am counting down the days /forums/images/graemlins/cool.gif
 
My argument too, Martyn. I do far more day boating in the Med compared to the longer distance cruising I used to do in the UK precisely because of the fuel cost here. I also cruise at a slower speed, about 18kts compared to 22-24kts in the UK for the same reason. I really do wish that high fuel costs forced peeps out of boating as there might be a few more moorings available /forums/images/graemlins/smile.gif
 
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It doesn't matter how many mpg a boat is using when working out the ecconomics of two different boats over a set journey. What does matter is the gph.

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Sorry, but that doesn't make any sense.
Better mpg means less money spent for the same journey, full stop.
 
I know a friend who put his 47 footer on the market the day we lost derg - he is going for a sailing cat because he cannot afford the fuel hike. There are many ways of getting out and changing but it will have a svabage effect on many boaters that I know.
 
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Kev
All I am saying is that I can choose to use SD boat 1 at 18 knots for the jorney and use X mpg

OR use Planing boat 2 of the same size at 26 knots for the same journey at the same X mpg

Both would have used the same amount of fuel.
The planing boat would be at sea less time.

This was my direct experience with those two boat types.

Do you accept these figures as sensible?

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Hi Paul, unfortunately not.

We have to compare apples with apples. So if the SD boat at 18 knots is running at 3000 rpm and the planning boat with the same engines as the SD is running at 3000rpm and doing 26 knots the planning boat will use less fuel than the SD for the same journey.
Trying to say different is the same as me trying to convince you that if I run one of my engines a 3000rpm for 20 mins (the SD time for making the journey) and the other engine at 3000rpm for 10 mins (the planning boats time for the journey) both engines would have burnt the same amount of fuel even though they both were running at 3000rpm but one twice as long as the other?
 
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Sorry, but that doesn't make any sense.
Better mpg means less money spent for the same journey, full stop.

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Only if as I said you are comparing apples with apples ie rpm agains rpm.

Another example would be two identicle boats with identicle engines but one is shaft drive the other is outdrive. The outdrive boat is more efficient and travels faster for the same rpm compared with the shaft drive.

Both leave chichester for cherburg and agree to travel at 3000 rpm, the outdrive boat travels at 26 knots @3000rpm, the shaftdrive travels at 23knots @3000 rpm. which is going to use the least fuel??? the outdrive boat of course.
Same principle applies when comparing planning and SD, apples with apples, you have to keep the energy used equal to get a fare comparison. Otherwise it would like be challenging me to a race round the M25 in identical cars and the winner is the one who uses the least fuel but you insist that I must travel as fast as I can and must thrash the car to it's limits. Apples with apples.....
 
Your example is fine: the outdrive boat has obviously the better mpg, in fact.
Think about it: the mpg is a measurement which summarize each and every effect (shafts, hull, you name it).
It's as simple as that.
That's why I argued against your statement "It doesn't matter how many mpg a boat is using when working out the ecconomics of two different boats over a set journey."
When working out the economics of two boats over a set journey, the mpg is actually the only meaningful number.
 
Mapism
Exactly ........ Its the measure of how may miles you do per gallon full stop - how that is achieved, hull shape, plished hull, shafts or if the girls on board are all blonde ios all taken into account with mpg.

We are not comparing apples with apples - wea are comparing two diiferent boats. All I am saying is that I prefer to travel in comfort at 18 knots using the same fuel as in less copmfort at 26 knots. Both use the same fuel. On get there faster, the other slower but with more comfort...... its as simple as that.
 
Sorry for your friend, if his decision was strictly driven by cash constraints.
But considering his range of choices, I guess he's one of those persons who would be happy to cruise with anything, as long as it floats... /forums/images/graemlins/smile.gif Good for him!
In my experience, that's very unusual.
I never met people who changed the type of boat for budget constraints.
They possibly delay the swap for a bigger boat, or downsize to a smaller one, or give up boating at all, in the worst cases.
But any D or SD MoBoer which I can think of, when they made the jump from planing boats (and all of them did, I can't remember of any pleasure MoBoer "born" with D or SD boats), it was always for different, non-economic reasons.
And btw, none of them would return to planing boats, but also this has nothing to see with economics.

PS: also my own reasons for moving from a planing boat to a trawler weren't economic, and as far as I understood, that could also be said for your current choices.
 
I'm sorry guys but you are talking rubbish. You need to have a level playing field. The level playing field is the amount of bhp the boat is using to move it at your desired speed.

It doesn't matter what boat the engine is in, planning or SD it will burn the same amount of fuel at a given RPM.

How can I make it more simple...

A planning boat has a single D4-260 engine, @ 3000rpm (as per earlier graph) it uses 34 litres per hour and will travel at 20 knots (realisticly it will do more). The boat undertakes a journey of 20 nautical miles. Obviously the journey takes 1 hour and the boat uses (as per earlier graph) 34 litres.

We take the engine out of the planning boat and put it in a SD boat and undertake the same 20 nautical mile journey @ 3000rpm but due to it being a SD boat @ 3000rpm the boat only travels at (optimistically) 15 knots. This journey will take 1 hour and twenty minutes @ 34 litres per hour (as per earlier graph)will use 45 litres. For the same journey that the Planning boat only used 34 litres. A saving of 11 litres. Agree?
 
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Agree?

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Definitely.
In fact, the first boat of your example has obviously a better mpg compared to the other one.
Just do the math.
 
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Agree?

[/ QUOTE ]
Definitely.
In fact, the first boat of your example has obviously a better mpg compared to the other one.
Just do the math.

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Yeehaaaaa

getting somewhere. Now we are comparing apples with apples (bhp being used) the miles per gallon works as one hull is more efficient than the other at given speeds.

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All that matters when measuring fuel consumption is miles per gallon. That is the only way of a meaningful fuel consumption measurement

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But Paul wasn't measuring apples with apples he was using mpg as the overriding factor when in fact mpg can only be used when comparing identical power outputs.

You can't expect a boat using 400 bhp to do 35 knots to be as efficient as a boat only using 150bhp to do 8 knots. You have to compare apples with apples ie the amount of power being used.

I rest my case your honour. gph and time taken is a more realistic measurment and is the only way to compare when boats are travelling at differnt speeds using different engines and different hull designs.
 
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mpg can only be used when comparing identical power outputs.

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Ahem. It's actually the opposite.
Mpg is the only economic measurement which you can apply regardless of power, hull, etc.
BUT...
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I rest my case your honour.

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...no prob, I can live with that! /forums/images/graemlins/grin.gif
 
I just had a new super duper power waher with hot water etc delivered to my lake for cleaning lake boats etc - just filled the engine oil resvervoir with the concentrated detergent and spent 2 hours involved in a very messy job getting back to square one!!!

For anyone who ever does this you can observe the simple physics of watching the deternegt sink into the inners of the engine as the oil stays on top - takes about 30 seconds as you realise what you just did and stand watching.

So I am not going to continue comparing apples with pears - i am going to pour myself a drink and dream of when i shall next have a boat!
/forums/images/graemlins/smile.gif
 
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Also ... and this is the key point of dispute - the SD and D boats offer decent, stable slow cruising with fuel efficiency and that cannot be matched by the planing boat. In as much as the planing boat has the edge on a higher speed for a given amount of fuel it loses out at its ability for decent slow speed cruising which when fule prices rise and rise as they will, will become the mode that more and more people choose to adopt. \hence the effect of a fuel increase on D and SD boats will be less than on planing boats.

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Yup, I accept that the SD/D boat will generally give a more comfy ride in the type of marginal conditions that force planing boats to slow to SD/D speeds but that does'nt mean that planing boats can't be cruised safely at these speeds as well. Personally I would rather be in a big heavy lump of an SD boat in rough conditions myself compared to a lighter planing boat and thats why, personally, I would choose a well designed SD hull for long distance cruising but my thinking would be that any fuel gains an SD boat obtained from cruising at slow speeds would be offset by those passages that I wanted to complete at higher speeds for reasons of time or weather
I could possibly agree with you that some peeps might look more at pure displacement boats in the future because they are happy to cruise at D speeds but for most of us with limited boating time, it's not a realistic option
In any case this whole issue of fuel consumption is a bit of a red herring on boats costing hundreds of thousands of pounds because any fuel efficiency gains are potentially more than offset by the biggest cost in boating ie depreciation. Better to buy a popular planing boat in demand and sell it a few years later for close to what you paid for it then buy an unknown SD boat nobody's heard of and lose your shirt (not a reference to the Marlow btw which is a fine boat). In fact the best buying decision a potential purchaser could make is to buy secondhand and save himself a lot more money than he could ever save on fuel
 
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