sleipner vector fins or seakeeper 16 for a 75 ft ?

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pascalsunseeker

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Dear All,

My current boat (Sunseeker predator 60 2012) has a seakeeper retrofit 2 years ago. About this stabilization system done by Nemo Marine France I am very happy, they did a very good job. The system itselfs works very well on anchor, cannot imagine that fins would be perform better. Now I am in the running to order a new boat a Sunseeker sportyacht 74 or Riva Ribelle 66. Sunseeker is very much promoting the zero speed fins from Sleipner. probably with this boat we gone do probably bigger trips then just the area of the cote d'azur. What I understand from this forum is that underway the fins work better, which is good. But on anchor are fins almost so good as the seakeeper or is there a big difference in stabilty ? can you help me with the choice between this 2 sytems ? The fins the manufactor (sunseeker) wants to install are the SPS66 VF1050. Riva is promoting the seakeeper system.

Best Regards,
Pascal
 
Depends how fast you want to go .
At planing speed with the riva - fins will drag .
I guess tge Riva is a faster boat to around 30 knots or more say mid 30 ,s
At speed you have dynamic stability.

Fins are better at runing / moving but will knocks knots off , 26 to 24 who cares, or 28to 26 ? In the Sunseeker .
But 35 to 29 in the Riva - I would care .

If you intend to travel at Displacement speed then fins as the performance knock off is not felt.
I new a guy who fitted fins to his Ergo 68 - lost 5 knots —— but saved the marriage - wife sea sick problem
 
thank you Portofino for your quiq response. the sunseeker will do what the factory told me 38 knots top speed with two pair of 1900 Man's(and fins installed) en the Riva 37 knots with two pair of 1550 Man's. I think mostly we gone cruise between 20-24 knots.
 
If you ONLY care about zero speed stabilisation then get the gyro.

That would be a strange thing though - you probably care about underway stabilisation. In that case you must get the fins. They are perfect underway even in a big sea. Gyros are useless

Obviously the stabilisation works in beam seas and quarter seas. Not head seas.

Consider this: fins are say 95% as good as gyros at anchor. Gyros are say 30% as good as fins underway in a big sea.

Porto is just incorrect about "dynamic stability". A boat going fast will be stable relative to the sea surface, but it cannot know where the horizon is. It is impossible for it to know. So it will roll in beam seas for sure, in line with the sea surface. With fins it will stay horizontal.

The drag of fins is tiny. You will lose about 1 knot at 30 knots. Porto's story about 5 knots is odd. Maybe it happened but it is totally not normal and it is not appropriate to present it as typical. Typical is 1 knot.

I have owned 2 x 78 foot boats in antibes with sps66 vf1050. They are awesome. My current squadron78 with those fins does 32 knots+ so the drag is insignificant. My brother also has the same fins on his 74 boat.

They are awesome and you will love them. I wouldn't buy a boat without them and at this size of boat I would always choose the sps66 vf1050.
 
Couple other things:

In an anchorage with big beam swell but little wind, e.g. Villefranche sometimes, fins make the boat swim forward. Not a big deal, but occasionally a nuisance. I would still buy them.

If you have small children swimming you might want to turn the fins off.
 
jfm said:
Obviously the stabilisation works in beam seas and quarter seas. Not head seas.
Click to expand...
Just in case Pascal might read this statement the way I did at first:
I'm pretty sure that what jfm means is that stabs (neither fins nor gyros) do nothing to reduce pitching, which is obviously the most annoying motion in head seas.
Otoh, when a head sea makes the boat pitch a lot, typically there are also some residual lateral forces which make the boat also roll, at least a bit.
And for this latter motion, stabs remain indeed as effective as in any other conditions, i.e. you would still pitch, but with no roll whatsoever.
In fact, I did try a few times to keep the stabs center locked while going exactly with the sea on the nose, but the additional bit of rolling with no stabs made the overall comfort perceivably worse.
That's because pitching alone is not that bad, as long as you adjust the boat speed to avoid crushing into every other wave.
Anyway, the bottom line is that I also would go for fins in such a big boat - particularly if aimed at cruising in the low 20s in spite of the fact that she's much faster.

As an aside, all these considerations apply to both the S/skr and the Riva.
There's absolutely no reason for choosing between gyros and fins based on the builder recommendations, which are strictly driven by their own considerations - prices negotiated with their suppliers first and foremost, but also others like internal spaces and assembling easiness.
In any sea conditions where one system performs better than the other, that would remain 100% true on both boats.

Anyway, all the very best for your final choice, which is indeed a nice problem to have. :encouragement:
Oh, and don't forget to post about that, possibly with pics!
 
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Pascal
Ferretti Group do a preview in Monaco the week end before the Cannes show .
You can add hock test drive everything .See for your self
And —— importantly speak to the Captains .
Your dealer should put you on the “ list “ of guests

Test it 1 st —— same with Sunseeker
 
thank you JFM for your advice this is very clear to me and I go for the fins, specially we want to do some bigger trips with this boat and then the fins would bring propably a lot of extra comfort for everyone on board. Do you drive your boat yourself or do you have crew (skipper or deckhand) on board ?
 
pascalsunseeker said:
thank you JFM for your advice this is very clear to me and I go for the fins, specially we want to do some bigger trips with this boat and then the fins would bring propably a lot of extra comfort for everyone on board. Do you drive your boat yourself or do you have crew (skipper or deckhand) on board ?
Click to expand...
I drive myself. I have crew but she is chef/stewardess/ tender driver. 1 person full time 52weeks, and I hire a second person (deckie/stewardess). for big holidays.

Mapism is correct in interpreting my comments, in his #6. Fins and gyros do not stop pitching but you still have then on in a head sea.
 
In your case pascal you may get what you are looking for by running Seakeeper and Interceptors. Seakeeper works underway while in displacement speeds and active interceptors can take over when you reach planing speed. With this setup you wont have the added drag and service requirement of fins.
 
It would be worth considering Humphree fins and interceptors.
You get the benefits of no servicing costs, no anchor walk as the fins spin 180 degrees when at anchor to gently pull against the , they run on 24 volts so can run without need for the generator and the system takes up much less space in the engine room.

JFM will now probably post his video of the noise that the first servo units made but the latest servos are almost silent.
 
aquatom said:
It would be worth considering Humphree fins and interceptors.
You get the benefits of no servicing costs, no anchor walk as the fins spin 180 degrees when at anchor to gently pull against the , they run on 24 volts so can run without need for the generator and the system takes up much less space in the engine room.

JFM will now probably post his video of the noise that the first servo units made but the latest servos are almost silent.
Click to expand...
Video? Videos you mean :D
Seriously if they have got quiet I wd be interested to know. Do you have a video? Do you know what changed from their early units? Difficult to make a very large reduction gearbox quiet at high rpm.
I don't think sunseeker will fit humphree anyway.
 
jfm said:
Difficult to make a very large reduction gearbox quiet at high rpm.
Click to expand...
Fwiw, I've yet to hear any quiet DC motor either - in fact, I suspect that this is the source of most of the Humphree noise, more than the g/box.
Can't be positive about that though, 'cause I've never seen the thing in flesh.

That said, obviously noise is only a problem when overnighting.
And there's only one way someone could make me keep the genset running at night: over my dead body.
Genset which obviously would be necessary also with the Humphree system, to avoid waking up with batteries completely dead.

Imho, if someone can't sleep in an anchorage with no stabs, there are only two alternatives:
1) the captain made a wrong choice, and should move somewhere else regardless of stabs;
2) whoever onboard can't sleep because of the boat motion, should rather consider a different hobby.
 
MapisM said:
Fwiw, I've yet to hear any quiet DC motor either - in fact, I suspect that this is the source of most of the Humphree noise, more than the g/box.
Can't be positive about that though, 'cause I've never seen the thing in flesh.

That said, obviously noise is only a problem when overnighting.
And there's only one way someone could make me keep the genset running at night: over my dead body.
Genset which obviously would be necessary also with the Humphree system, to avoid waking up with batteries completely dead.

Imho, if someone can't sleep in an anchorage with no stabs, there are only two alternatives:
1) the captain made a wrong choice, and should move somewhere else regardless of stabs;
2) whoever onboard can't sleep because of the boat motion, should rather consider a different hobby.
Click to expand...
Yup, I generally agree that for the most part . I have only run stabs/generator overnight twice in my life, and your #1 applied ( mea culpa) :D
 
Well, if that's a consolation, I also did - just once.
And as you know, I didn't have star stabs, but it was possibly the hottest night I ever experienced in my whole life, with absolutely ZERO wind.
I even tried to go sleeping on the f/b, but it was too hot even up there, so eventually I had to resort to genset + a/c.
And I didn't sleep well anyway, because of the noise. Aaaarumph! :nonchalance:
 
Its what you get used to. We have air con at home & when oldest son moved out he had to have it installed in new house because he missed the fan noise & couldn't sleep. (trouble being newer units are quieter :ambivalence:)
 
I think it’s genset noise ?
FWIW our frigomar AC is as silent at night so,s not to disturb sleep .
You can hear the genset @ anchor though so we like most ( small boats ) @ anchor @ night turn it off and just open windows ,the breeze seems enough to vent air .
As Mapish says boat motion I hope actually helps rock you off to sleep @ anchor along with reasonable silence .

How ever sound travels more so @ night and calmer anchorages ,some bigger boats - threshold being around this size do keep one geny on .
It might be possible if speccing a new build to meet the “ configuration team / personal designers “ from Sunseeker or Riva and specifically request a second smaller ( less sound ,or more able to effective soundproof dims wise ? )
If you use Frigomar advance D.C. brushless motor air con kit , that’s silent too BUT importantly uses a significant LESS amperage demand = smaller power / geny for night running @ anchor .
You would have a bigger traditional main geny for Day time as well .

So having gone down the silent geny + Aircon route @ build , that opens up some sort of reciprocal stabilisation @ anchor ,to be quiet @ night , to sleep ?

So now if a so called “ sporty planing boat “ - Large Sunseeker or Riva - stab @ anchor - it’s loooking at a gyro .
Again on a big boat they can be soundproofed at build I would have thought much easier than retro fit ?
That way you are not compromising the performance ,- reflect a moment at residuals ?

Earlier on I mentioned “ speak to the Captains “
I was on a Pershing 115 new boat recently.
Owner ( Swiss guys ) was a serial Sunseeker owner - had 4 all Preditors , last being a 115 irrc ? - same as his Pershing L wise - he got rid of it after 18 months for the very reasons we are discussing here- refinement .
They finned the Pred on Sunnys recommendation @ build .
It was exactly as this thread says - if I understand the issues correctly?
Lost speed , —- which was important
Noisey at night - the motors under bunks ,
Kids swimming issues
Some docking align side issues .

The reason after 4 Sunys he reluctantly switched to Pershing was exactly what i,am saying —— they listened and fitted gyros + second geny .
Pershing would cruise @37 knots economic if such a word can be used ,
SUNY was high 20.s low 30,s because of the fins , burned more fuel than the P at this slower speed .
Everything on the P was silent
The geny , Aircon on , the gyro on

That’s why you need to speak to Ferretti group guys and try before you buy .
I think engineering wise they have solved silent running of genset s , gyros and Aircon .
 
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100% agree on Sleipner Fins. The guy that bought old boat (52 footer) just spent 35 hours in up to 3M swells and has been in touch to express awe re the smaller sps55 system we fitted- " we thought the inclinometer in the wheelhouse was broken" the sps 66 even better. For my part i very regularly run the genset all night - love the stabs and aircon and the kids won`t sleep (or set foot on boat) if stabs not on .so i might be fine rolling along but so far as 9 year olds concerned i would have to be in port every night without the sleipners
 
dear all,

yesterday I have done a seatrial in Poole with the new sunseeker predator 74 with the sleipner fins. this boat had the smallest 1550's Man and the performance was very well even with fins on, we had a maximum speed of 35.1 knts with half load fuel and water so this is good. underway the boat was very stable with the fins but we tested at zero speed and this was a disappointment for me and my wife. the sea had a swell axpproximatly from 0.3-0.4 m and the boat was sometimes rolling sometimes not this was very strange. we pushed the fins on and off and even the sunseeker people couldn't say it the system was off or on when they not looked on the display. i told them when I put my seakeeper on or off be sure you gone know very well without looking on the display. it all felt for me very unnatural in comparison with my current seakeeper on my sunseeker. The boat herself is beautiful and the navigating is top. we knew the slot of this boat was this week because it's the sportyacht 74 which is on display at dusseldorf show january 2019. So we signed a contract for this model with the fins but I asked the question to install a small gyro SK 9 on it. The problem is that engineroom is good filled with the 1900's which I order. Now Ross Donohou is looking with his engineers what's possible. in this case I would use the fins underway and the sk9 on anchor. but if the space was there I would go for the seakeeper 16. Can somewhone explain me how I can post a photo of the boat we tested yesterday. regards Pascal
 
Hi, Pascal - I have nil experience of owning stabilised boats, but remember the experience of being on jfm's Squadron 78 with the fins 'on', at an event with 30+ people milling about and climbing on and off board and it was as steady as the dockside itself. Very impressive. I hope the set-up you've ordered works well for you.
 
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