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Old 12-09-2007, 06:47   #1
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Roll Control Devices

Hello all,

Has anyone had any experience with the various roll control devices out there intended to make life on the anchor more pleasant? I am considering two outriggers supported by toe rail and masthead and am hoping for some input on which device seems to work the best.
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Old 12-09-2007, 07:23   #2
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Tie a nylon line to yer anchor chain, lead the line aft to a cockpit winch, then winch the bow into the waves, no more rolling...
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Old 12-09-2007, 13:45   #3
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One common one is called a "flopper stopper". Easy enough to make your own versions. One easy version is a piece of ply with a weight on one side and a line bridle connecting to the four points. As the boat dips down, the "lighter" side of the ply lifts and the ply drops in the water. As the boat lifts, the ply pulls tight on the line bridle.
After saying all that, I have never tried it. It seems to complicated when it is easier to use a stern line to pull the bow around, or do as CSY suggested.
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Old 12-09-2007, 13:53   #4
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These work great.

West Marine: Rock N Roll Stabilizer - 30'+ Product Display

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Old 12-09-2007, 16:10   #5
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Anti-roll devices

Although the name "Flopper-Stopper" has seem to have acquired a universal meaning like "Xerox" it is a brand name although I don't know if they are still being manufactured. They are the least effective of all the devices that I have witnessed.

I agree with Steve. The Magma that WestMarine sells is a design originally called "Sea-Cure". In my opinion it works the best for the least square footage of stowage space because it folds up like a book, which is how it works anyway.

If the device is deployed to seaward it is the most effective although it will work on the other side. It is not necessary to deploy two, port and starboard although this might not seem obvious. If the boat's rotational acceleration is limited by the anti-roll device in only one direction then the motion may be unbelievably most tolerable.

What Wheels points out is true when there is only one set of wave motion, in general I've found that, although it may not be noticeably visible, there are other sets of wave motion that bridling to the rode will not solve. In addition, with tidal and wind changes the boat can swing around with the anti-roll device still keeping the motion tolerable.

I have used these for decades (similar to the one sold by WM) and even made my own. One visiting couple aboard my boat who had not been acclimated complained of feeling quite queasy at anchor. After I deployed the anti-roll device they immediately felt fine.

On a sailboat I prefer to triangulate a downwind pole, attached to the mast and deployed as close to beam-on as possible, by using a spare halyard to the end of the pole and a fore and aft guy from a bow cleat to the end of the pole and back to an aft cleat. Adjust the halyard so that the pole nearly bisects the angle made by the halyard and the downline attached to the anti-roll device. Make the downline sufficiently long so as to miss the keel when a current might carry the device towards the boat or when the boat swings (sailing at anchor) or veers towards where the device hangs in the water. Make the downwind pole length adjustment (if you have an adjustable pole) such that the device hangs as far as possible from the side of the boat for maximum leverage against rolling.

I have a solid long boathook that will just reach the downline for retreival otherwise you have to attach a nuisance retreival line like the one shown in the photo that Steve's link shows. If you use shackles to attach the device make SURE that they are safety wired else you risk losing it as I did one time. In only 20 feet of clear water I dove around the boat for a long time and never found it!
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Old 12-09-2007, 17:18   #6
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Actually while we were cruising we had two of them. One went over the side on the extended whisker pole. The flopper stopper line was ten feet long with a rubber snubber on it to soften the valve action. The other one went off the tip of our bowsprit.

While others rocked and rolled, we just sat there.

Both of them were stored as close as possible to the point of use. We made a sunbrella flat bag which was fastened to the lifelines next to the mast. Deployment took only a few minutes and was the first thing whenever we anchored if the possibility of rolling was even suspected.

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Old 12-09-2007, 17:41   #7
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Two outriggers? You're almost there. How about the ultimate roll control device. The multihull.
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Old 12-09-2007, 18:21   #8
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Anti-roll multi hull?

If you examine the problem of discomfort due to wave action on a hull at anchor you come to realize that it is not the amount of roll that bothers humans it is the angular acceleration that makes life miserable. The nasty action is a snap roll.

Multi-hulls are not anti-roll devices they in fact make for a very nasty angular acceleration to wave action. To be sure they do not roll as much as a mono-hull yet what roll that they DO have can be quite nasty and very uncomfortable.
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Old 12-09-2007, 19:12   #9
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Quote:
Originally Posted by Rick View Post
If you examine the problem of discomfort due to wave action on a hull at anchor you come to realize that it is not the amount of roll that bothers humans it is the angular acceleration that makes life miserable. The nasty action is a snap roll.

Multi-hulls are not anti-roll devices they in fact make for a very nasty angular acceleration to wave action. To be sure they do not roll as much as a mono-hull yet what roll that they DO have can be quite nasty and very uncomfortable.
I don't agree with this at all. The amplitude of the roll is at least as much of a problem as its frequency. It's the roll angle acheived that throws you out of bed, dumps the contents of lockers on the floor, and makes the crockery clatter. The really annoying part is that mono's can roll violently in very little swell. Sometimes you can barely see the waves. If the frequency matches the roll frequency of the boat, they roll, and the roll gets bigger and bigger.

In similar conditions a multi will barely move. If it's rough enough a multi will have a rocking motion, which could possibly become uncomfortable, but the anchorage would have to be quite rough for that to happen. The mono's would all have left hours before then.

On topic, for a mono, pushing the boom out to the shrouds, and hanging a stainless bucket from it under the water can help reduce the roll quite a lot.
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Old 12-09-2007, 20:25   #10
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roll amplitude

I don't believe that you have ever experienced much rolling variations. Once I hove to in a storm with huge waves. They were so big that I could not look at them without having to fight down the fear. The boat would ride up up up the wave and heel way over so that if you looked out a nose port all you saw was water...REAL close to the port. Then the boat would slowly roll back over and ride down down down.

The amplitude as well as angle of heel was great yet the ride was quite comfortable (because we were used to being at sea). We took a hot shower and went to bed for a few hours and got quite rested.

So, again, I say that discomfort depends upon angular acceleration not amount of roll or amplitude. Having a multihull will in no way prevent discomfort given a rapid approaching set of waves. I have been on several multihulls and experienced such discomfort that I did not have on a multihull with an anti-roll device deployed. It can and must also be deployed on a multihull. Which hull one has makes some conditions bad on one and O.K. on another. Change the conditions and the role (pun intended) will be reversed.
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Old 12-09-2007, 21:27   #11
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Er, the motion hove-to in a storm is a little different from rolling at anchor, which is what this thread is actually about.........Hove-to you will experience a reasonably constant angle of heel - the sails resist rolling motion. At anchor you don't normally have sails set, so the boat rolls much more freely.
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Old 13-09-2007, 06:13   #12
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Thank you all for your inputs. I wouldn't have guessed that a single device provides a better motion than two opposed devices. I also like the suggestion regarding a second device to dampen pitching.
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Old 13-09-2007, 15:00   #13
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Yes, being hove to is not the same as anchoring. In large waves the boat does not stay at a constant angle of heel by any means. My point is that large rolling excursions (which I experienced) with low values of angular acceleration can be relatively comfortable and objects below do not necessarily get thrown about as one might think.

My contention is that so-called anti-roll devices such as the Magma reduce one's feeling of nausea by preventing high values of angular acceleration of the roll. Yes, the peak values of angular heel are also reduced yet there will still be roll. The roll that remains is quite tame by comparison.

Every boat has a different point of resonance when laying to beam-to seas. When that resonance happens the action will be uncomfortable and the resonance can be removed or radically reduced by the anti-roll device. Any floating object other than a perfect sphere has at least one resonance frequency that wave pertubations will excite giving rolling and/or pitching motion that a different object nearby will not exhibit if the nearby object has different resonant frequencies and modes. This is why in one anchorage one boat will feel that it is "rolly" and if you look at some other boats nearby they may not be moving much at all!
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