The costs of pulling the throttles back

[dylanwinter]

In another thread about cameras ogaryo posted this film of his Solent journey in an S 28

as a sailor of a 23 foot one tonne boat with a 6hp engine who has just burned three gallons of four star on the journey from the Humber to the Scotland I was curious about the costs involved in being able to say "hold tight" and shoving those levers back, watching that bow rise and hearing the whoops of joy of your passengers

I asked him how much per minute that thrill was costing him

and he said he does not keep a record of costs

I fully understand

but he is very happy for his fellow forumites to make educted guesses

so here is the excellent film



any guesses then as to the overall and variable costs of such a thrill

 

[colingr]

Well worth every penny but I'd tidy up those scruffy fender lines before starting the camera

 

[dylanwinter]

you guys

Well worth every penny but I'd tidy up those scruffy fender lines before starting the camera

are as bad as the sailors

D

 

[Whitelighter]

KAD32 engines. At a fast ish cruise it guess 20lph per engine.

So 50lph @ £1.10/litre. £55 so about 90p a minute.

 

[Nick_H]

KAD32 engines. At a fast ish cruise it guess 20lph per engine.

So 50lph @ £1.10/litre. £55 so about 90p a minute.

Has Gary got two and a half engines in his boat?

 

[DAKA]

I was curious about the costs involved in being able to say "hold tight" and shoving those levers back,

any guesses then as to the overall and variable costs of such a thrill

Ive never worked out the cost of cruising @25knots but your question asks how much to pull the throttles back which I have calculated.

Pulling the throttles back (if we slow down for 23ft raggies) and getting back on the plane costs about £4.37 based on a 60/40 split.

Hence why many fast boats tend to get on the plane and stay on the plane, leaving or entering a popular harbour can be expensive if you power up and down for each boat, bit like walking into a sailing club and buying everyone a pint .

Next time you meet a stinker in a bar Dylan you should buy the guy a pint
I reckon you owe quite a few after such a long cruise, loads must have wasted their fuel on your comfort

 

[dylanwinter]

Ive never worked out the cost of cruising @25knots but your question asks how much to pull the throttles back which I have calculated.

Pulling the throttles back (if we slow down for 23ft raggies) and getting back on the plane costs about £4.37 based on a 60/40 split.

Hence why many fast boats tend to get on the plane and stay on the plane, leaving or entering a popular harbour can be expensive if you power up and down for each boat, bit like walking into a sailing club and buying everyone a pint .

Next time you meet a stinker in a bar Dylan you should buy the guy a pint
I reckon you owe quite a few after such a long cruise, loads must have wasted their fuel on your comfort

wow.... is that figure really true

it costs nearly a fiver every time you slow down

bloody nora man!

 

[Elessar]

wow.... is that figure really true

it costs nearly a fiver every time you slow down

bloody nora man!

this is daka land.

My 10 tonne, 40 fter uses just over 2 l per mile at displacement speed and just over 4 l per nautical mile when planing.

There is a bit in the middle, between say 8 and 16 knots, when fuel use per mile is a lot higher. I don't stay at that speed for obvious reasons. So slowing down and speeding up does cost something, but slowing down and staying slow saves something.

 

[dylanwinter]

this is daka land.

My 10 tonne, 40 fter uses just over 2 l per mile at displacement speed and just over 4 l per nautical mile when planing.

There is a bit in the middle, between say 8 and 16 knots, when fuel use per mile is a lot higher. I don't stay at that speed for obvious reasons. So slowing down and speeding up does cost something, but slowing down and staying slow saves something.

but is he close when he says that dropping off the plane and then back on to it again after slowing down for a raggie, canoist, naked sunbather, nun on a paddle board could cost £5?

I can feel a sympathetic column coming on

D

 

[Keith-i]

Roughly 15mpg at 5kts and 1.5mpg at 15. Shan't tell you what that equates in fuel cost to as it'll just upset you all. 32ft semi-displacement with 265hp.

 

[Deleted User YDKXO]

staying slow saves something.

Yes it saves fuel but it adds engine hours. Stating the bleedin' obvious, a boat cruising at 7kts will accumulate 3 times as many hours as a boat cruising at 21kts and that is an issue when it comes to selling the boat because as we know, engine hours affects the used value. So, I do wonder whether any fuel saving from cruising at 7kts is more than eaten up by an increase in depreciation. Unless and until every planing boat owner becomes accustomed to cruising at slow speed and used boat buyers learn to accept higher engine hours as a result, slowing down might be self defeating in terms of money saved

 

[dylanwinter]

Roughly 15mpg at 5kts and 1.5mpg at 15. Shan't tell you what that equates in fuel cost to as it'll just upset you all. 32ft semi-displacement with 265hp.

so how does that equate to per minute of planing fun?

 

[Elessar]

but is he close when he says that dropping off the plane and then back on to it again after slowing down for a raggie, canoist, naked sunbather, nun on a paddle board could cost £5?

I can feel a sympathetic column coming on

D

£5 extra - I don't think so, but if you're thinking of every litre of fuel like that anyway you won't enjoy your boat. I just fill it out of the boat fund and enjoy myself. You don't think, oh it's windy today thats £x of the bill for new sails. If you did a £/mile for some racey sails it would make diesel look cheap!!

 

[Elessar]

Yes it saves fuel but it adds engine hours. Stating the bleedin' obvious, a boat cruising at 7kts will accumulate 3 times as many hours as a boat cruising at 21kts and that is an issue when it comes to selling the boat because as we know, engine hours affects the used value. So, I do wonder whether any fuel saving from cruising at 7kts is more than eaten up by an increase in depreciation. Unless and until every planing boat owner becomes accustomed to cruising at slow speed and used boat buyers learn to accept higher engine hours as a result, slowing down might be self defeating in terms of money saved

And to also state the bleeding obvious is 3 times as many hours out on the boat - which is what I do it for, it's just that those hours cost less in fuel. But I don't care about that either, I go at the speed that takes my fancy. There are slightly more efficient modes of transport, that's not what my boat is most of the time.

 

[DAKA]

but is he close when he says that dropping off the plane and then back on to it again after slowing down for a raggie, canoist, naked sunbather, nun on a paddle board could cost £5?

I can feel a sympathetic column coming on

D

Hi Dylan,
you know me well enough to realize that I dont post without first giving some consideration, my sums have been doubted so I will attempt to explain the logic for those who havent given the question as much thought as I have.

Anyone with a modern diesel car who sets their MPG computer to instantaneous knows
cruising speed = 40 mpg+
and hard acceleration = 6mpg
hang a caravan on the back to simulate the effects of trying to get over the hump and it drops even lower !

using Elessars boat as an example 25knot cruise = .9 nmpg cruise divided by factor 40 over 6 = .135 nmpg it will cost Elessar a pint of beer to get back onto the plane @ £1.10 60/40 split

 

[dylanwinter]

Hi Dylan,
you know me well enough to realize that I dont post without first giving some consideration, my sums have been doubted so I will attempt to explain the logic for those who havent given the question as much thought as I have.

Anyone with a modern diesel car who sets their MPG computer to instantaneous knows
cruising speed = 40 mpg+
and hard acceleration = 6mpg
hang a caravan on the back to simulate the effects of trying to get over the hump and it drops even lower !

using Elessars boat as an example 25knot cruise = .9 nmpg cruise divided by factor 40 over 6 = .135 nmpg it will cost Elessar £4.99 near as dam it to get back onto the plane @ £1.10 60/40 split

wow, wow and thrice wow

D

 

[Whitelighter]

Has Gary got two and a half engines in his boat?

good point. i meant to adjust the per engine figure to 45. doh

 

[colingr]

are as bad as the sailors

D

Just coz I'm not a raggie don't mean that I have low smartness standards

 

[jfm]

so how does that equate to per minute of planing fun?

I do 700 litres an hour at 30knots, and fuel is £1.20/litre. So that's £14 per minute. Or about £1 every 4 seconds, which happens to be very easy to visualise because it is like standing there inserting £1 coins continuously into a slot machine!

At more modest cruising speed the thing drops from 700 to 400 litres/hour and therefore the £14 drops to £8 per minute.

Another way to look at it, bearing in mind it's say 15-20 litres/mile at any planning speed, is £20/mile

But a boat was never designed as a cheap mode of transport.

 

[kashurst]

I'm a closet raggie (just spent a week sailing a Hanse 400 ) don't be fooled into thinking sailing is free, don't forget the cost of sail cleaning, replacing halyards and shrouds and periodically a new set of sails. MOBOs pay per mile, sail boats get big big bills periodically.