Interesting vid on Seakeeper gyro stabiliser system

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Deleted User YDKXO

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HERE and website here Seakeeper

I don't know about other forumites but this season I have been cruising slower to save fuel, often at displacement speeds. The trouble is that planing boats are not designed for displacement speeds and often have an unpleasant rolling or corkscrewing motion in anything other than a straight on head or following sea. On one trip, I felt quite seasick and had to speed up to feel better
This Seakeeper system looks similar to the Mitsubishi system fitted by Ferretti but the big difference is that they'll sell it to anyone and you don't have to buy a new Ferretti to get it! It even looks possible to retrofit it as it requires a space less than 1x1x1m and uses about 1.5Kw of power when up and running which means that a relatively small gennie can power it
I was thinking that a stabilizer system like this could make displacement cruising in a planing boat a lot more pleasant and could even make some boaters buy a planing boat for extended cruising rather than a SD or full on D boat
What does the panel think?
 
I agree with all your thoughts above

but I think the Mits one works about 10-20% better, now it just depends the price difference between the 2...

have you ever tryed your Ferretti at low planning speeds at about 15 knots, usually Ferretti are good for these as they have a moderate vee aft, but also the planning speeds of most Fer models is always under 15 knots, some of them plane even at 10 mostly because they dont use tunnels
 
Seakeeper claim that their system works better than the Mitsu system because the flywheel spins in a vacuum and can therefore rotate faster for the same power input. See FAQ's
Yes, you're right, my Ferretti planes at about 11-12kts (with max tab down) but my calculations suggest that there's no big fuel saving at this speed, maybe 10% less than at 20-22kts. To make a big fuel saving, I have to go at D speeds
 
Interesting. Any idea about cost? A friend is having one (don't know from which maker) put into his upcoming Sunseeker 70 and mentioned around US$50K. Small change on a big boat, but quite a lot on something worth less.
 
Dunno about the cost but I guess it must be in that order
 
Probably TRAC, they seem to be the preferred system used by most UK manufacturers. They're also what I have on my boat and imho they are excellent although I don't have the STAR (stabilisation at rest) which is really only for those who are going to spend a lot of time at anchor, usually the larger vessels who will also be running their generators all the time.
 
Price is around $50k, I enquired a year ago. It's quite noticable that it has significantly less damping effect on the Azi 50, than it does on the 40 footer on Seakeepers web site video, so I doubt it would have much effect at all on a Sunseeker 70, unless two or more were fitted.

On Magnum's new 84 there are two options, the Tracs active fins, or a gyro, but I think it's the Mitsubishi (don't know how that works with the Ferretti exclusivity arrangement?)

I think most planing boat owners will still use their boats at planing speed most the time, so the gyro wont add much under way. The real advantage for me is at anchor. With most boating areas getting busier, and the boats getting bigger, residual wash is a big problem in all but the most protected anchorages.

I did consider getting the Seakeeper retro fitted to my P57, and got details and prices from them, but I reckon the effectiveness tails off quickly with boat displacement, so if it's 50% effective on an Azi 50, I reckon it'll be nearer 25% on a 25 tonne 58 footer, and I think my flopper stoppers achieve at least that. It would also take up most of the lazarette, and i've no confidence in the local French engineers to fit it properly.
 
I think the idea is that you fit multiple units to larger boats. Their website mentions fitting 5 units to a 34meter boat. Could be that a 50 footer is the limit for 1 unit and you need 2 or more units for anything larger
Agree that a stabilizer would be well worth having in most Med anchorages. My point about planing boats was praps not well made. What I meant to say was that, if you're considering buying a boat for long distance cruising, you're probably thinking about a boat that's going to be reasonably comfortable at D speeds in which case you're probably only looking at D or SD boats but, as we know, SD boats are generally less fuel efficient than planing boats at planing speeds. So it seems to me that if you can fit an effective stabilizer to a planing boat, you've got a boat that would be comfy at D speeds but most efficient at planing speeds
Take something like a Fleming 55. Probably more stable and comfy than a planing boat at D speeds but awful juicy at 15kts. Would a stabilised Princess 57 be a better choice if you plan a mix of D and planing speed cruising? Obviously there are a lot of other considerations but a stabilizer might tilt the balance towards the planing boat for some peeps. It would certainly make me think
 
I've been watching the progress of this for some time now and having an AZ50 here in the UK, it's been particularly interesting to watch the sea trials in their AZ50. I must admit, I'm often put off anchoraging here in the Solent as too much rolling makes me sick /forums/images/graemlins/confused.gif ....so I tend to head to another marina for the day/night. I wonder if Azimut are planning to fit this gyro as an option to new AZ50's from now on? Also curious as a retrofit if it could be squeezed down the lazarette hole.

Interesting stuff though and gyros still fascinate me - reminds me of being a kid and having one of though hand-held toy gyros....... /forums/images/graemlins/tongue.gif
 
Good post Mike. At first I visualised some external fin type devices and couldn't see the retro-fit but after watching the video I was impressed. It seems to take little room and a small amount of power for a large result.

Brilliant - just wish I had invented it /forums/images/graemlins/frown.gif
 
They work to an extent. They don't have much effect in minor swell, but as the roll gets bigger they start to have more effect. I'd say they reduce roll by about a quarter to a third on average. In big swells though, the version 2, much lighter, flopper stoppers can't sink fast enough, so the damping is reduced. Version 3 should be better, and will be installed for next year /forums/images/graemlins/grin.gif
 
[ QUOTE ]
Obviously there are a lot of other considerations but a stabilizer might tilt the balance towards the planing boat for some peeps.

[/ QUOTE ]Agreed, on both respects.
I mean, it's true that a stabilized planing boat might be more appealing to those who wish to use her occasionally also for long(ish), slow and economic passages.
But when that kind of usage really becomes your main target, then the "lot of other considerations" becomes relevant, and invariably point to full D hulls. In fact, there are also other reasons - aside from the stabs - why heavy trawlers are more comfortable and safer than P hulls. As an example, they suffer much less the "corkscrewing motion" which you mentioned, and against which the stabs can do very little.
In other words, I don't think that P stabilized boats will steal one single customer to Nordhavn and the likes.
But as a compromise for those who aren't yet ready to live without the option of speed, they can definitely make sense.
 
[ QUOTE ]
In other words, I don't think that P stabilized boats will steal one single customer to Nordhavn and the likes.
But as a compromise for those who aren't yet ready to live without the option of speed, they can definitely make sense.

[/ QUOTE ]

These are people like me then. I plan to semi retire in a few years and buy a boat for extended cruising (assuming the credit crunch doesn't f*** me up). Most of the time I want to go at D speeds but I want the ability to go faster when I want to beat the weather or simply because I don't have time to go slow. The best type of boat for this is a SD boat like Fleming, Aquastar, Trader or whatever because these boats are more comfortable at D speeds than a P boat. The trouble is that at SD speeds, this type of boat uses more fuel than a P boat. So, for my intended cruising, maybe a stabilised P boat is more attractive than a SD boat. For sure, a stabilized P boat will not be considered by somebody looking for a D boat like Nordhavn, Selene etc but for people like me, just maybe?
 
Absolutely, it's the need for speed and I need it /forums/images/graemlins/smile.gif
 
Short answer, yes.

If you want to be able to occasionally beat the weather, or to go faster when you fancy, then a P stabilized boats is a sensible choice.
And PY is right when he says that this is a common view in marina talks.
But based on my own experience, I wouldn't trade the comfort, safety and economy of full D boats with anything else, for various reasons.
Each to their own of course.
 
Whoops, I missed your post re.speed while posting my previous reply.
See, actually I'm also a speedboat fan.
To some extent, that's also a reason why I'm a trawler fan when talking about cruising boats: if you really like speedboats, a planing flybridge is the equivalent of a Cheers beer for an alcoholic.
Just give an air-entrapment catamaran a try, at 80+ kts.
After that, the only effect of a 30kts spin on a big boat will be to get nervous about all that shaking and rattle, coupled with the feeling of burning a lot of money just to go slowly anyhow.
 
Interesting stuff mike and (Nick) - thanks. I'm in same camp as you Deleted User: I like D speeds for long trips but like to P when I want/need to, and I find the fuel mpg of Selene et al disappointing

Alas I just don't see how this thing fits on most boats. It certianly wouldn't fit in mine. The main gyro box is 800x700x1000. A washing machine is 800 x 600 x 600 roughly. so this baby is like a washing machine that is 1 and 2/3 the width. You'd be very lucky to have that sort of space lying around. Even the ancilliaries are big, though they could be fitted somewhere with a bit of ingenuity. And it weighs half a tonne, sheesh. All ok provided you are happy to give up the crew cabin or something

I'm inclined to think that exterior fins are a better answer, even on a P boat. Sunseeker have done them on the current Pred82 (and maybe other models) including m/y Champneys that is in lots of their ads, and anecdotally they work fine
 
Agree space may be a problem with retro fit, although I could actually fit one in my lazarette by moving some other stuff around, but I reckon it could be accommodated quite easily if it was a designed in option. It helps that it doesn't need to be on the centreline, so could maybe have genny one side, gyro the other to also balance weight.

I'd be very tempted to spec one if buying a sub 50 footer, or even retrofit one, but I think we'd need two to have enough effect on a 58 footer, and I certainly couldn't fit two in.
 
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