Prestige 500 fly IPS 600 at Displacement speed

[paulrackstraw]

I have purchased a 2015 Prestige 500 fly. The boat is currently in France and I will be flying over in late August to deliver the boat to her new marina in the Trieste area in Italy in the Northern Adriatic. The trip is about 1400nm. I have a few questions which will help me plan for this trip.

I understand the balance between speed and fuel consumption. I also know that it is not good to cruise a diesel engine at low revs for an extended period of time. Can anyone advise how long one can run at 8 to 9 knots and how long one should run it faster on a plane (>3000rpm) to clear motor out after running at displacement speed.

Does anyone have real life cruising fuel consumption for the Prestige 500.

My sailing catamaran I often run with one engine. At displacement speeds is this an option with IPS drives?

What are the operating hours of the fuel stations in the marina's in France, Italy and Croatia?

What are the best weather apps to use in that area. We will be going up to Hyeres area, across to Corsica, Elba Islands, down the Italian coast, through the straights of Messina, across the boot of Italy, up the Italian coast and then across to Croatia. Up the Croatia coast to Trieste.

 

[volvopaul]

I have purchased a 2015 Prestige 500 fly. The boat is currently in France and I will be flying over in late August to deliver the boat to her new marina in the Trieste area in Italy in the Northern Adriatic. The trip is about 1400nm. I have a few questions which will help me plan for this trip.

I understand the balance between speed and fuel consumption. I also know that it is not good to cruise a diesel engine at low revs for an extended period of time. Can anyone advise how long one can run at 8 to 9 knots and how long one should run it faster on a plane (>3000rpm) to clear motor out after running at displacement speed.

Does anyone have real life cruising fuel consumption for the Prestige 500.

You have a very modern engine therefore there is no problem running it a slow rpm , you may have the option of real live fuel data from the engines displayed on the plotter or EVC small screen data , if it’s a new boat get the dealer to upgrade the software to give this option, that way you can put the boat through the speed and rev range to give MPG .
My persona view is to run both engines as the steering will be vague and there would be doubts the autopilot would work correctly on one engine.

 

[BartW]

good advice from VP regarding fuel consumption
I have no experienjce with your boat / engine models
I would alway's run with both engines, on some boats its not favourable to run on one engine for different reasons...

nice and interesting trip !
I have done most of it, but not in one season

can't answer your Q about operation hours of fuel stations,
but I would advice to plan the trip so that you can go for fuel in normal "marine office hours"
and call or mail the fuel station in advance, and make a appointment for getting fuel, or discuss the possibility's

It makes sense to plan for buying tax free fuel in Porto Montenegro (50% cheaper) but you need to make a appointment a few day's in advance there !

some tracks on this route are very nice ! make sure you can experience some of that !

for wheather prediction I alway's use Windfinder Pro (superforecast)
as a second source I use LammA Meteo (Italy / ligurian sea)
I use another in Croatia, but forgot the name, tbc

 

[MapisM]

What are the best weather apps to use in that area. We will be going up to Hyeres area, across to Corsica, Elba Islands, down the Italian coast, through the straights of Messina, across the boot of Italy, up the Italian coast and then across to Croatia. Up the Croatia coast to Trieste.

Sounds like a plan! All the best, and don't forget that we love cruise reports, here in the asylum - apropos, welcome to it.

Sea-conditions and Windy and VentuSky are among my preferred apps/websites, but there are also others, and nowadays I think that most actually rely on the same source, so once you will find your preferred one, it's not much worth bothering to cross-check with others.

Not much to add to what volvopaul posted ref. the usage of your setup, aside from suggesting you to take what he said as carved in stone.
You might not know since you are new around here, but he's our resident bible on anything VP-related! :encouragement:

 

[MapisM]

as a second source I use LammA Meteo (Italy / ligurian sea)
I use another in Croatia, but forgot the name, tbc

Good point ref. LaMMA, I forgot to mention it but that's another one which I also find reliable.
For HR, is possibly this one that you have in mind?

 

[MedMilo]

You have a very modern engine therefore there is no problem running it a slow rpm.

At the risk of venturing off topic, I was very interested to read this because I'm still very unclear as to whether regular slow running DOES or DOES NOT cause bores to glaze and all manner of other engine issues?! My boat has fin stabilisers which allow it to run beautifully and pretty endlessly at 10 knots / 1000 rpm. But I've in the past been told that to run for hours on end at this speed will be bad for my Caterpillar C18 1150hp engines. So I try to do 20 minutes at 1800rpm every two hours. But it's often a bit of a bore to stick to this routine of speeding up so often...

 

[Portofino]

At the risk of venturing off topic, I was very interested to read this because I'm still very unclear as to whether regular slow running DOES or DOES NOT cause bores to glaze and all manner of other engine issues?! My boat has fin stabilisers which allow it to run beautifully and pretty endlessly at 10 knots / 1000 rpm. But I've in the past been told that to run for hours on end at this speed will be bad for my Caterpillar C18 1150hp engines. So I try to do 20 minutes at 1800rpm every two hours. But it's often a bit of a bore to stick to this routine of speeding up so often...

Two aspects need splitting out and treating separately.
Over fuelling with analogue delivered fuel because the things works on a mech cam and plunger optimised for the correct range of operation .
Lower than this and a slight or moderate excess fuel goes slightly unburnt and gum forms that sticks to the honing and hence the glazing .
Modern CR pulse delivered fuel eliminates this as just the correct amount is delivered across the whole range inc 1000 rpm or what ever .Hence VP - both the forumite and factory are correct .

How ever the Second tier of thought is agglomeration , the formation and mitigating factors decreasing this .
Theses no getting round low Exhaust Gas Temps at 1000 rpm and excess properly burnt contents even with CR ( the right fuel dose ) .This partial burnt ( cos it’s not high enough temp basically) stuff is the real wear stuff short of adding pumice to your oil - only joking folks

What sort of bores do you have ?
What sort of rings ?
What’s your oil like ?
What’s your oil change Fq ?

They say minimum agglomeration occurs at around 550 / 630 EGT .
For reference for me that’s N of 1750 rpm .
1000 rpm and it plummets to 2-300 IRC’s deemed too low .

Then mix in how long are you gonna keep it 1000 hrs ,3000 hrs 10,000 hrs .
If running at 1000 rpm predominantly 1/2 s the engine life from say 20000 to 10000 hrs so what ?
How ever if issues start to creep in at say an easily a achievable say 1500 hrs due to not so resilient liner material or not so resistant theses days rings ........ Longish oil Fq change intervals etc etc.

Just make an informed choice.

Back to the OP
Let the wind and waves dictate the pace .
There will be days of port bound , lost days due to wind and days of pancake calm in which case gun it leapfrog halts .

It’s such a long trip you can’t pre plan it really and keep to that .

 

[MapisM]

I'm still very unclear as to whether regular slow running DOES or DOES NOT cause bores to glaze and all manner of other engine issues?!

My understanding, based on several talks on this matter with all sort of official engineers (Cat, VP, MAN, MTU), some with more white hairs than myself (and all speaking based on experience rather than web searches ), is that the answer to your question is yes it does, in principle.
Also with modern electronic engines, albeit to a somewhat lesser extent.

BUT the key point is, how long does it take for this process to be meaningful?
And in spite of the fact that this is to some extent a debate about how long a piece of string is, all of these folks, bar none, agree that this concern is totally pointless in pleasure boats.
I mean, yes, if you install an E (light duty) rated engine like yours in a similar size fishing trawler that runs 24/7 at 8 knots, with the prop demanding 100hp (if that) at 800rpm, you are likely to have the problems you mention, sooner or later.
Same goes for a Nordhavn, which can spends weeks crossing oceans, with nowhere to stop in between.
Which is exactly the reason why you won't find your engines in any of these boats.
Though coming to think of it, Nordhavn did fit a couple of C18 in one of their boats, but that's the massive 96, and with the continuous duty version of them, rated for 450 or so (yes, much less than half!) hp at 1800 rather than 2300rpm.

So, here's my personal conclusion, fwiw: at 10kts, the longest passage you can make, anywhere in the Med, takes less than 24 hours.
If you fancy doing it 100% at D speed, just do it, and maybe give the engines a spin for 20 mins or so just before arriving.
But don't lose your sleep if you would even forget this last bit of "Italian tuning". Your engines weren't built in Modena!

Personally, what I find more difficult now that I'm back to fastish boating, is just to resist the temptation to at least bring the boat up on the plane, even if at just 18kts or so.
But that's also because my particular boat really comes into her own only at P speed (even better if in the upper half of 20s), and ain't stabilized.

 

[Nigelpickin]

I had a prestige 500 (s) for three years.
We sailed it from Falmouth to the Algarve - 1700 miles and mainly we stayed just below displacement speed, around 7.5kts. Rpm just less than 1000 and Consumption at this speed was around 15l per hour.
Best cruise for the boat at planing speed is around 20knots @ just under 3000 rpm - you’ll be around 110l per hour.
Max speed will be 28 knots or thereabouts - that’s gong to cost around 160lph.

Range when planing is around 220 nm- when plodding along more like 800 nm.

Fuel burn/gauges on my boat were very accurate.

In reality - if you get sea from behind or ahead you’re fine to stay at low speed, there’s no point going up to displacement speed, around 8 knots, as your consumption will rise and so will the bow!

Anything from the side and you’ll want to get the boat up and over before you start losing wine glasses and lunch.

We never ran with one engine as someone suggested to me that it might cause wear on the pod transmission - not sure if that’s true......

 

[Deleted User YDKXO]

Possibly the manual for your boat may have instructions for running on one engine only. In the manual for my boat, it states that if one engine is not running and the prop is left to freewheel, it is critical to keep an eye on gearbox oil temp and if it exceeds 80degC, engage gear to stop the prop freewheeling even though this will cause more drag

I do a lot of cruising in my 63ft planing boat at displacement speed but generally I cruise at planing speed for about 20mins in every hour on average. This is not because it says so in any manual but simply because I believe it is beneficial for the engines to be put under load on a regular basis

 

[MapisM]

if one engine is not running and the prop is left to freewheel, it is critical to keep an eye on gearbox oil temp and if it exceeds 80degC, engage gear to stop the prop freewheeling even though this will cause more drag

Did you ever try that, M? I suspect that on your boat, if one engine is disabled for any reason, you actually can't engage its gear.
I'm non pretending to know better than Ferretti in general, but it wouldn't be the first time that I see weird manual instructions...

 

[Bajansailor]

Here is a Boat Test report for the Prestige 500 with a detailed record of fuel consumption during their sea trial.

https://www.boattest.com/review/prestige-yachts/2486_500s

 

[Deleted User YDKXO]

Did you ever try that, M? I suspect that on your boat, if one engine is disabled for any reason, you actually can't engage its gear.
I'm non pretending to know better than Ferretti in general, but it wouldn't be the first time that I see weird manual instructions...

Yes I suspect that too but this is what the manual says!

In case one engine stops due to a failure and the gear box is in idle position, during navigation keep constantly an eye on the oil temperature of the gear box connected with the failed system.
The propeller shaft is kept rotating thanks to the water flow through the propeller, under these conditions also some parts of the gearbox are kept rotating.
Should the temperature increase excessively over 80 °C, lock the propeller shaft by engaging the gearbox: in this way the resistance will be higher, because the gearbox is jammed, but oil will not overheat.

 

[Whitelighter]

Alternate engines every couple of hours? Should alleviate this?

 

[MedMilo]

Two aspects need splitting out and treating separately.
Over fuelling with analogue delivered fuel because the things works on a mech cam and plunger optimised for the correct range of operation .
Lower than this and a slight or moderate excess fuel goes slightly unburnt and gum forms that sticks to the honing and hence the glazing .
Modern CR pulse delivered fuel eliminates this as just the correct amount is delivered across the whole range inc 1000 rpm or what ever .Hence VP - both the forumite and factory are correct .

How ever the Second tier of thought is agglomeration , the formation and mitigating factors decreasing this .
Theses no getting round low Exhaust Gas Temps at 1000 rpm and excess properly burnt contents even with CR ( the right fuel dose ) .This partial burnt ( cos it’s not high enough temp basically) stuff is the real wear stuff short of adding pumice to your oil - only joking folks

What sort of bores do you have ?
What sort of rings ?
What’s your oil like ?
What’s your oil change Fq ?

They say minimum agglomeration occurs at around 550 / 630 EGT .
For reference for me that’s N of 1750 rpm .
1000 rpm and it plummets to 2-300 IRC’s deemed too low .

Then mix in how long are you gonna keep it 1000 hrs ,3000 hrs 10,000 hrs .
If running at 1000 rpm predominantly 1/2 s the engine life from say 20000 to 10000 hrs so what ?
How ever if issues start to creep in at say an easily a achievable say 1500 hrs due to not so resilient liner material or not so resistant theses days rings ........ Longish oil Fq change intervals etc etc.

Just make an informed choice.

Thanks for this, all understood (ish!). I suspect that in reality more than a third of my engine hours are spent at 'normal' 1800 rpm type levels and also I change engine oil each season, which equates to around every 200/250 hours (which I imagine is pretty frequently relative to the frequency with which these engines' oil is changed in some of other applications they're found in (buses etc)).

Can't really answer the question about the type of bores and rings I have (!) but at a boat show a few years ago the chaps on the Finnings stand said that if I start with a fast blast to get temps up and then follow the 20 mins at 1800 rpm every two hours routine, all will be good with the engines. But that if I didn't follow this regime I might be storing a problem for the future, so it seems this is something that needs to be managed....

 

[jrudge]

1400 miles at 8 knots is 175 hours running.

More to the point do you really want to do 175 hours at displacement speeds on a planning hull? I would not. It will be boring slow and uncomfortable not to mention given the age of the boat probably doubling its engine hours.

One engine on a twin usually runs the power steering and on one engine they don’t track straight.

I would use it as it’s designed speed or stick it on a ship / truck.

 

[MedMilo]

I agree with jrudge that to plan to do 175 hours at displacement speed is a big call - even on the basis of doing, say 25% at planing speed, with inevitable weather delays that's likely to take two or three weeks. Personally I'd either stick it on a low loader (which will probably work out cheaper) or, depending on how much time you can free up, would take a few weeks to get it part of the way then leave it in a safe marina and fly back to do the next leg. Perfect way to spend the autumn months and a better bet than cruising past Corsica, Elba, Sardinia, Amalfi, Aeolians, etc etc etc with having a bit of time to enjoy them!! But obviously that plan might not suit your situation...

 

[Portofino]

I change engine oil each season, which equates to around every 200/250 hours (which I imagine is pretty frequently relative to the frequency with which these engines' oil is changed in some of other applications they're found in (buses etc)).

Can't really answer the question about the type of bores and rings ...

I know I was just highlighting and hopefully simultaneously eliminating the “ Ive ran mine at diddly squat rpm since time began “ response .This is because there’s too many variables in the actual materials and construction of each engine .
Variables like on that list you don’t know about as an owner .

Oil - the oil should be changed annually because the oil's additive package deteriorates over time and gets further used up holding contaminants in suspension. This is not related to engine operation (mileage) just time.

We get this regularly in classic car forums today , the oil change Fq .Same answer .Its not the hrs or mileage, it’s not the hammering of the long chain molecules ie the lubrication property of low use age - your 250 hrs compared to a bus / truck it’s the additive package.Thinking about it there’s gonna be more crap held in suspension with low running temps so the swing o meter should go to more Fq changes .
Realise we not talking about a 2 x5 L picked off a self at holfords like a car .

Back to the Op
If you wind up doing a long slow D speed then change the engine oil .
Just as a similar story I factored in Del trips costs when hunting , fuel at av cruise, flights and even a skipper into the buying equation.
What worried me was not the fuel bill Naples / Cannes it was the sustainability. Will it last ? Is ought on this new to me boat gonna knacker ?
We had done a significant amount of yard prep agreed at purchase, stuff like fresh lift and antifoul , anodes , in the ER filters replaced etc .
We just set cruise at 26/27 knots all the way an easy 1750 and something rpm backing down in a beam on F8 to 1650 as we cross from Elba to Corsica, wind coming up from the S .We we’re running parallel to the wave and either sitting in a valley or riding on a ridge .
D speed would have been awful and basically untenable.

A cautionary tale a friend of mine bought a IPS 600 boat last Autumn from a reputable broker .It was a stock boat located in Roma .He is based in Cannes and part of the negotiations was they ( dealer / broker ) deliver it .
A pod packed up near Pisa and it spent the winter there’s awaiting VP and others to fix it .€25000 later in bills - shown to my mate btw it arrived Mid Feb .Dealer / Broker stud the bill under a 3 month warranty thingy .
It had 125 hrs when he bought it and was fully serviced etc etc with a nice history file .
Water got in the gears apparently told .

So is yours ever had a 10 hr day ?

 

[paulrackstraw]

Thanks so much for all the input, really appreciate everyone’s wise wisdom. Sadly this trip will not be a long cruising one as I only have 2.5 weeks to do the trip. I don’t plan to go at displacement speed the whole way, I was thinking more for the odd overnight run where refueling might be an issue, or where sea conditions dictate slower running. We are planning a two week trip in France and Corsica in June/July before this trip. Next year the aim is to do a four month trip along Italy, Slovenia, Croatia, Montenegro, Slovenia and Greece depending how far we get.

 

[Nigelpickin]

‘We jus set cruise at 26/27 knots all the way an easy 1750 and something rpm backing down in a beam on F8 to 1650 as we cross from Elba to Corsica, wind coming up from the S .We we’re running parallel to the wave and either sitting in a valley or riding on a ridge .
D speed would have been awful and basically untenable’

Wow, how long were you beam on in a force 8? That’s pretty impressive! 25’ of that kind of sea/swell is bad enough from behind but from the side would be pretty scary. Planing atop that takes some balls - we had 20’ Breaking wakes once from the side but I put them behind us and waited for things to calm down.