New Seakeeper gyro

I just read that Seakeeper came out with a new gyro stabilizer for smaller boats.

The Seakeeper 5 is for boats up to 50' and 20 tons.

It uses 2 kw of 110 volt power, is 30"x30"x25" and weighs 720 lbs

MSRP is $29k

With the smaller size and lower cost this might just be the ticket.

I've thought about stabilization quite a bit for my boat. I'm going to go look but I think I can jockey some stuff around and find room.

At a minimum it's something I think is worth seriously considering. I really like that it works without forward motion. That's great for rolly anchorages and drift fishing,
.

ksanders said:

I just read that Seakeeper came out with a new gyro stabilizer for smaller boats.

The Seakeeper 5 is for boats up to 50' and 20 tons.

It uses 2 kw of 110 volt power, is 30"x30"x25" and weighs 720 lbs

MSRP is $29k

With the smaller size and lower cost this might just be the ticket.

I've thought about stabilization quite a bit for my boat. I'm going to go look but I think I can jockey some stuff around and find room.

At a minimum it's something I think is worth seriously considering. I really like that it works without forward motion. That's great for rolly anchorages and drift fishing,
.

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That's about the weight of 4 people; impressive! A little Honda suitcase could probably run it at 2kw max draw.

Good pricing too at under 30k......

The big advantage I see is no fins to get damaged in shallow canals or in harbours, plus no drag at higher speeds.

Rustybarge said:

That's about the weight of 4 people; impressive! A little Honda suitcase could probably run it at 2kw max draw.

Good pricing too at under 30k......

The big advantage I see is no fins to get damaged in shallow canals or in harbours, plus no drag at higher speeds.

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The big advantage is it works at anchor or even at the dock.

Once you've had at anchor stabilization and just like after the first time you've had a boat with underway stabilizers, you'll never want to be without it again.

Actually they have been talking of this smaller version for the last two years. I agree with all the above advantages.

Now, some big disadvantages, for me at least:

Must run the gen all the time to run the seakeeper,
Cost, $30k means $40k and that's still 4 times what I could afford or wanted to pay,

And the MAIN disadvantage, is in a retrofit.

No matter how strong they made the stringers in your engine room, no way was anything in there ever designed to take the torque loads the seakeeper will make.

I do like it for a new build, if I intended to run the gen most of the time.

Wxx3 said:

Actually they have been talking of this smaller version for the last two years. I agree with all the above advantages.

Now, some big disadvantages, for me at least:

Must run the gen all the time to run the seakeeper,
Cost, $30k means $40k and that's still 4 times what I could afford or wanted to pay,

And the MAIN disadvantage, is in a retrofit.

No matter how strong they made the stringers in your engine room, no way was anything in there ever designed to take the torque loads the seakeeper will make.

I do like it for a new build, if I intended to run the gen most of the time.

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Hi Richard,

Hope all's going well for you in Waterford. Did you get the info about the low bridge on the Shannon; it's a good time to start cruising now the spring weather
Has arrived.

I was just thinking that the torque para vanes exert on the hull doesn't seem to stress it too much, would a Seakeeper exert much more on the stringers?

Another plus is that in calm running or quiet anchorages, it and gennie can be turned off. I find that I only rarely desire stabilization, but when I want it it would REALLY BE NICE!!

My gut feel is that the forces on the stringers would not be that high, but have nothing beyond gut feel to back that up. Rolling is the boat moving at it's natural frequency, and in any such system the forces needed to begin or end that motion generally are not that large. Even then, where it is located needs to be structurally beefy for the weight alone.

I wonder what the power requirements vs. roll intensity look like. Does it take 2kW to spin in idle conditions? Or just when it working against a roll?

Maybe a DC version could be an idea.

Hull loads are high with the Seakeaper- 13,000 NM or 10,000 ft lbs according to their literature, but no different than paravanes or hydraulic vanes. It takes so much torque to stop roll no matter how it is generated.

The real problem is that they are concentrated with the Seakeeper. With a 30" width that means that the 10,000 ft lbs produces about 8,000 lbs of force at the outboard edge of the Seakeeper housing. This will almost certainly require a fabricated aluminum frame to distribute the load transversely.

Once that force is transferred say 5' outboard, it gets down to about 2,000 lbs which sounds a bit more manageable. If it were mounted next to a structural bulkhead, the aluminum frame could transfer the load to the bulkhead/hull/stringer system. Otherwise I suspect it would take a good bit of glass work to layup cross members to transfer the load down to the hull and stringers.

It is all doable, and probably no worse than reinforcing a hull to take paravane or hydraulic vane forces. But since these are applied way out near the maximum beam, they are lower, although a paravane system has to deal with wave and potential impact and sea weed generated forces.

The real question is how well does it work? Any feedback on the bigger models? Seakeeper provides test data on a Krogen and Grand Banks, but both tests are done at anchor facing beam seas. It does cut roll in half which is better than almost anything else can do at anchor. But what is the performance like underway.

David

A good friend of mine is the West Coast rep for SeaKeeper. He's been talking to us about installing one on our boat, and it does look enticing.

It can be installed centerline or off centerline, and once up and operating, it fairly low power draw. I was impressed with the model at the Seattle Boat show.

The ideal install location for us would be where our genset currently resides. Push comes to shove, we could make it work, but at this point I'm not totally committed.

For sure, this would be a better install during a build or total refit.

Pau Hana said:

A good friend of mine is the West Coast rep for SeaKeeper. He's been talking to us about installing one on our boat, and it does look enticing.

It can be installed centerline or off centerline, and once up and operating, it fairly low power draw. I was impressed with the model at the Seattle Boat show.

The ideal install location for us would be where our genset currently resides. Push comes to shove, we could make it work, but at this point I'm not totally committed.

For sure, this would be a better install during a build or total refit.

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There's a guy on the mbm forum who retro fitted the bigger Seakeeper 9 to his boat, and with all the extra costs of the fit out etc etc it ended up being twice the original price of the gyro unit.

I think each different application needs a special frame and pick up points.

As mentioned, hull integrity and redesign on a retrofit would prove the challenge. Of the several retrofits I have read about all were on solid FRP hulls. My guess is an older composite hull would prove to be an expensive and technically challenging endeavor, well above the purchase price of about $30K.

Active at rest stabilizers are an option too, Twistedtree has these as do several others. For vessels running gensets most of the time, either option seems attractive, with space limitations and no genset requirement - when cruising - favoring the fins on slower vessels.

P&MY magazine has tested many vessels with Seakeepers during the past few years, all reports as I recall were positive. The latest I read with interest was on my favorite boat of the moment, an MJM 50. But they do require an operating genset. Ski, a low voltage motor and wiring would be larger in comparison to 110/220V wouldn't it?

RickB started a good thread about a year ago on this subject. If I were to consider a retrofit, my first consult would be with RickB.

I'd love to have one of these, even at that price, but I don't kid myself about the forces involved here. At over 7000 lbs. ft. at 30 or so inch spread, eventually (if not imediately), such forces would debone my boat like a chef like a overdone fish. Unless I could spread those forces out to the cap-rail (full beam), I couldn't use it.

As a guy thats been considering stabilization for some time here are some issues I've identified with either fin or gyro stabilization.

Fins

The actual fins for our boat would be placed behind the forward head vanity and under the berth in the "bunk" stateroom. This would require dis assembly of these internal areas, and significant hull build up in these areas. This is an extremely labor intensive process.

The hydraulic pump would be located on one of the transmissions, and a 5 gallon hydraulic tank would be located in the engine space as well.

I was quoted $27K from Wesmar for the basic gyro and fins of a proper size to provide underway syabilization. For the advanced gyro and larger fins to provide at rest stabilization the parts cost rose to $39K. Wesmar has done several 4788 installations so they have allot of the engineering done for my boat.

As far as installation fins require significant specialized labor skills that I do not possess. The fiberglass layup at minimum would have to be outsourced. I could do the mechanical and electrical work myself. I'm estimating it would take a "season" to do the install by the time I do everything and get it all cleaned up.

Advantages of fins are that they do not require the generator to operate.

Disadvantages are that the specialized labor for the fiberglass work is not readily available in Seward Alaska.

Since I sometimes run my boat at a higher than displacement speed cruise, my performance would be impacted. The simple fact is that fins will add drag and at a higher power setting the drag needs to be accounted for.

SEAKEEPER GYRO

The Gyro unit would be located in the lazarette. As Pete indicated the best place would be where my generator currently is. On my boat the two main stringers run the length of the boat and would be a perfect place to bolt the gyro unit to.

Moving my generator and re-arranging my lazarette is something I could easily accomplish myself with my existing skill set.

Bolting in the gyro is also something I could accomplish myself. I would consult Seakeeper and probably have a set of brackets to fit my stringers made up. They also have the potential of bonding the unit and or the brackets to the stringers to help dissipate the loads.

I'm estimating that the lazarette re-arrangement would take me a week to do. Installing the gyro might take me another week but I think it would go much quicker than that if I had mounting hardware pre-fabricated.

Gyro advantages are that the thing works at anchor and while drift fishing.
Running the generator is a disadvantage. This disadvantage is mitigated by the fact that I have a brand new Northern Lights generator that is very quiet and designed for continuous operation.

Weight is a disadvantage of the gyro, but we need to remember that the fins are not without weight themselves. The weight of the fins is a few hundred pounds total but the weight is distributed better with the fins than the gyro.

This is interesting enough that I'm going to start studying the feasibility of fitting the gyro into my lazarette.


There has been allot of discussion in this thread about loads being applied to the boat. We need to keep in mind that these are not shock loads, they are loads that are applied to counteract wave action loads.

With fins for example, in an installation on my boat they have been successful with a 2'X2' backer being glassed into the hull beneath each fin with only one edge having a connection to an existing stringer, and that stringer not being one of the two "main" stringers on the boat.

The gyro the unit would be attached to the two main stringers and the loads would be applied to those stringers. Those stringers run the length of the boat and by nature would dissipate the loads into the hull areas which are attached the entire length.

The only worry I have with the gyro is to spread the loads applied to the stringers over as large an area as possible. If for example I had a mount (think engine mount here) fabricated then the force would all be applied to the mount creating large compression loads in a small area. If I was able to use a plate for example and spread that load over a 3' area of stringer then the loads per square inch would be much smaller.

Kevin

Who would you use to perform the required re-design of the hull and field testing to insure no delamination or saturation from new in the composite hull? Neither of these are negatives, just preparatory pre-install tasks IMHO.

sunchaser said:

Kevin

Who would you use to perform the required re-design of the hull and field testing to insure no delamination or saturation from new in the composite hull? Neither of these are negatives, just preparatory pre-install tasks IMHO.

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To be honest there is little chance of my engaging a naval architect for this. If I have to do that the project will stall and never move forward.

I think this is just like the 2' backer plates that have been successfully used for fin installations in my hull. I'd bet that no naval architect was engaged, and no in depth hull studies were conducted.

I don't want to call it over engineering because its not, but at some point a decision has to be made, just like any other modification to a boat.

I would bet that the boats that seakeeper gyro's have been retrofitted to did not have their hulls re-designed either, but I'll of course check. I'd be foolish not to, but again if a hull re-design is required then the project stops right here right now.

These hi output alternators would run the gyros: Alternators: Mastervolt Alternator 24/150 Incl 3-Stage Charge Regulator (M48524150)

100amps output at 1000 engine revs!
150 amps at 1900 revs.

I see the new Seakeeper is rated for boats up to 20T. What's the displacement of your Bayliner? I would have guessed a good bit more than that.

Regardless, if you do the install, please post the whole process, especially the results. I think we would all be real interested. I simply don't believe magazine reviews. They are in the business of promoting the industry, and are all happy thoughts, all the time. Some are worse than others, but make no mistake what their job is.

twistedtree said:

Regardless, if you do the install, please post the whole process, especially the results. .

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Peter, you did a nice job on reporting your thruster install. A very good template for reporting on a worthwhile project IMHO.

Kevin,

David did a nice job of explaining what I was trying to say.

I would think that you should be able to get some information or help from Bayliner. They know who they designed and built your boat. I would think, they could tell you exactly what type of frame was needed and where.

Kevin: I think you've got the right boat to do this with and if I had a 4788 I'd be seriously thinking about it too, but I'm not sure about the lazarette location in an uneven sea. Wouldn't the stabilization forces at one end of the boat tend to somewhat warp into directional forces at the other, swinging the bow port or starboard?

Unless I missed it in this thread, I did not see mentioned that the gyro takes 40 minutes or so to reach speed. Plan ahead for beam seas!

The Seakeeper website is replete with information. This is not an experiment on Kevin's part, Seakeepers are the real deal with over 2000 in use on craft big and small. Google them at:

www.seakeeper.com

hmason said:

Unless I missed it in this thread, I did not see mentioned that the gyro takes 40 minutes or so to reach speed. Plan ahead for beam seas!

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Don't people do that in general? Plus the extra time you take to let the system warm up pays off once you anchor up in that anchorage at the end of the day that no one else can use but you because of the surge or swell that would have them rolling all night but your the one enjoying a comfortable meal and nights rest.

Once you have at rest sabilization it can open up a whole new world of anchorages.

Does anyone here have them on their boat, or will Kevin be our guinea pig? I'd love to hear some first-hand owner experience. There is plenty of fin stabilizer experience out there, but so far no gyro that I've heard. If there are really 2000 of them deployed, where are the customers?

twistedtree said:

Does anyone here have them on their boat, or will Kevin be our guinea pig? I'd love to hear some first-hand owner experience. There is plenty of fin stabilizer experience out there, but so far no gyro that I've heard. If there are really 2000 of them deployed, where are the customers?

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Wait a minute!!! You've got me already installing the thing

I do not know who all the customers are. I do not know if the little one is the proper size for my boat. I do not even know for sure if my boats hull type is proper for the unit. Remember I have a fiberglass hull with a foam core. It has two nice and thick fiberglass layers with the foam in between them. There's never been a problem with a Bayliner hull that I know of, but this is new territory.

All I know about the gyros is the several magazine articles I've read over the last couple years and what I've seen on the web sites.

What I do know is that the units are coming down in size and price enough to warrant some serious due dilligance.

What I do know is that if it works as advertised it would be a very nice addition to my boat.

So, the quest for information is on. First step is to contact the manufacturer and ask them which unit they recommend for my boat and for their anticipated roll data for my boat.

After that we start looking at the other installation aspects, but first steps first.

Navigator had a gyro on MV Kekada, and if his build blog is still accessible there will likely be some details of it. It was not a Seakeeper though, but rather a cheaper brand. It may not have been as good as Seakeeper. But, Don indicated that the gyro gave his wife seasickness due to a 'snap-back' characteristic and that he would never have another one. Unfortunately he did not get the opportunity to test as thoroughly as he wanted due to the explosion and loss of the vessel.

As we know, active fins have accelerometers in their control boxes and the fins are continuously adjusting. They are variable rate devices that can adjust the amount of righting moment applied. Navigator's gyro probably did not have that capability, and I have no idea whether the Seakeeper does either. But it seems to me to be important for attenuating roll in a comfortable manner. I hope Kevin's research can shed some light on this. Next boat show I should try and get more info from them as well....

ksanders said:

Wait a minute!!! You've got me already installing the thing

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Come on, take one for the team

Looks like seakeeper has hydraulic cylinders that can rotate the gyro assembly relative to roll axis. So it is more than a simple gyro. This rotation presumably can be controlled actively in manner similar to fin stabilizers.

Regarding the forces on boat structure, I do see the numbers posted for torque. But I really think the actual forces in normal ops will be substantially less than these posted maximums. So yep you need to design for the max, but in actual use I think getting into a hull ripping fatigue situation is not that likely. Just going by gut feel here. Damping an oscillation at natural frequency usually involves small to moderate forces. The flopper stopper analogy is appropriate. I would try to span across as many structural elements though, as much as practical.

That Seakeeper gyro unit is a really interesting option, for sure. Do you have info on the power draws after "the ball" is up to speed? Maybe the unit can run on the inverter power after a point.

I'm no expert, that's for sure, but I do wonder about the placement of he unit in the lazarette. Intuitively I would think placement would be best amidships. Perhaps a friendly phone call to an independent naval architect might answer that question.


Jim
Sent from my iPad using Trawler Forum

Too late Kevin, since that anchor episode you have been coronated the official Trawler Forum beta tester. Shut up and write the check already