Reducing roll while anchored or moored.

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We have a Gyro that is on whenever we are running the boat. I only run it while stationary if conditions are very bad for environmental reasons.

I have been thinking of a flopper stopper for a few years now and watching the guy next to me the past week rolling a heck of a lot less than we are, it’s time to do it.

I know extending it away from the boat horizontally like sailboats do with their boom is best to get a larger Moment arm to resist the boat rolling. But my plan is to just hang one on a midship cleat, possibly both sides.

The folding plates shown below appear to be the most popular, but I have seen people use the stacked ones as well.

Thoughts as to the best solution, or other products out there I may be missing?

I'm going to ignore the arguing later in this thread and return to your original post.

The strength of a gyro is when anchored, secondary is their benefit at slow speed. They are deficient at high speed. You have a boat well equipped for anchoring and using the gyro. You acknowledge how it helps in really bad conditions, but you choose not to run it otherwise.

You cite "for environmental reasons." I'd like to hear specifically what environmental reasons you're referring to. The energy and fuel usage would be very minimal. Noise is minimal or can be made so. I just can find, and do find, other things to do for the environment than to sit rocking back and forth in a boat equipped to prevent that.

I'm not a gyro purchaser because we travel at higher speed, although gyro combined with Naiad has become popular with our builder and if we anchored more, we would retrofit one boat. However, you have a great boat equipped often with gyros and for which it seems you already have the perfect solution. Just trying to understand better.
 
Our boat came with Paravane stabilizers, which are great, and we use them all the time. I tried putting them out at anchor and they don't work at all. They are too small, and they swim in circles as they pull up and down and twist up the spectra line I have them on like crazy. I bought some 14"x34" pieces of 1/4" marine aluminum and made a 4 point spectra bridal passed through holes drilled in the corners. I picked the size based on what would fit in my lazaret easily. They don't sink quite fast enough, but they help a huge amount. It would probably be even better if they were a little bigger, or had flaps to sink faster. They also make a good "Swing" for my kid to sit on while attached to the hydraulic dingy lift and I can give her a thrill dip in the very cold water. We call it "The big dip" and it has become a summertime favorite.

Our boat is 40' and about 23K lb.
 

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FlopStopper

These look interesting.

FlopStopper.com

:thumb: I have these for my GB 36. I have the single boom which I use to hang one outboard, and I got another to hang from the opposite side midship cleat, but have not done so yet. I would think they recover and drop faster than the inverted cones or drogues, getting them ready more quickly for the up roll. I would like to figure a way to rig a pole on the opposite side because theoretically it should be all about the distance from mid line to slow the roll, but so far have not been able to do so on the GB.
 
Okay I just bit the bullet and coughed up for a Flop Stopper - should get here in time for our next trip to the islands. Hopefully it's a meaningful improvement over the hats.

Envious of you PNW guys with your flat calm anchorages!
 
Flipper stoppers

Hard chines generate turbulence during a roll so naturally damp the roll more quickly than a round chine design. Things like roll period and snap back are determined by other factors including displacement, hull form, and weight distribution. Naval architects design the weight distribution in a boat to manage these factors (ballast, tanks, engines, superstructure). For example, a sailboat without a mast has a rapid roll with hard snap back because it needs the weight of the mast to balance the weight of the keel. In fact, this is why dismasted sailboats are far more likely to be rolled over. You really have to be on a boat to know what kind of motion it has. Our hard chine V-bottom has a slow roll with gentle snap back (Ed Monk did his job well).
I bought a Selene 38 in Hong Kong as a retirement livaboard in Thailand etc. I anchored out almost all of the time due to lack of marinas. Consequently, after so research I built my own system of booms and "fish" The booms I fashioned from timber and a stainless fitting on the outboard end. The inboard end I used a spinnaker pole fitting which I attached to a large cleat that I bolted to two nylon clamp plates either side of the large rope bulwark hole. This provides a centre point for the pole and still provides a cleat for midship docking. The "fish are from a design seen in a yachting magazine some years ago and are a 500mm triangle with a tune in one corner filled with the lead from a dive weigh ie one kilo. This ensures the plates dive one the boat rolls towards the side they are deployed.
The system is usable underway and is very effective, although not used frequently. At anchor, one deployed is usually quit sufficient, two out are really good. I can deploy one in minutes and frequency do. The final 'fish" ended up being cut from 3/8 marine aluminium and the 'fin' was bolted at 90 degrees with pieces of right angles. Whilst this might sound like a "Heath Robinson" set up, I can assure readers that it is not and really looks and works very well. The original was fabricated in steel and painted to ensure it worked ok. When towed the (2) 'fish' reduce speed by 3/4 knot Towing one has been tried, is effective but needs 10degrees of wheel to counteract the drag on one side so not recommended. The poles, varnished, are 9foot long and suspended from the top of the short (strong/heavy) standard mast, They are raised/lowered with a simple block and pulley, and look 'fishing boat' Not to everyones taste/eye but having now travelled about 24,000 miles with them I'd be reluctant not have them. That said, a new owner, or I, could unbolt the lot in an hour and dispose of them to make the boat look tidy if required. They really work and have provided many many hours of comfort in rolly anchors in my travels in SE Asia and now Turkey.
 
Been looking at N40s as the next boat. Their original tooling included what’s necessary for fish. The attachment point is filled on most all of them but only secured by sealant. So easy peasy to to remove and put in the needed gear for fish. The poles and other bits are standard forspar stuff that I’m well familiar with as it’s just about the same as spinnaker stuff except Al instead of cf. Think it makes huge sense to have both fins and fish. Belt and suspenders. Complicated and simple. Easy to deploy with a switch flicked and a bit of effort. Nordhavn site makes it look like you lose 0.3 for stabilization but can’t figure out if both deployed do you lose by added number given for each or is it less or more. Would think they are far enough away from each other each ones parasitic drag isn’t effected by the others. Is that true? Also at anchor is it ever a problem that a poled out floppier stopper entangles in a fin?
 
Been looking at N40s as the next boat. Their original tooling included what’s necessary for fish. The attachment point is filled on most all of them but only secured by sealant. So easy peasy to to remove and put in the needed gear for fish. The poles and other bits are standard forspar stuff that I’m well familiar with as it’s just about the same as spinnaker stuff except Al instead of cf. Think it makes huge sense to have both fins and fish. Belt and suspenders. Complicated and simple. Easy to deploy with a switch flicked and a bit of effort. Nordhavn site makes it look like you lose 0.3 for stabilization but can’t figure out if both deployed do you lose by added number given for each or is it less or more. Would think they are far enough away from each other each ones parasitic drag isn’t effected by the others. Is that true? Also at anchor is it ever a problem that a poled out floppier stopper entangles in a fin?

Observations:

1. pretty sure the paravanes on N40's are purpose-built, not off-the-shelf. The flopper-stopper rig is Forespar, but paravanes are custom rigged, probably from a set of plans from PAE. They may have the fabrication schedule available, especially since many were built at the Pacific Seacraft yard in SoCal.

2. PAE/Nordhavn typically rigged paravanes with electric winches to retrieve the fish; and knee-height push button switches in the cockpit to activate. There is some wiring involved beyond just building the strong-back for the paravanes

3. I don't recall how long the poles were on Nordhavn's, but probably in the 16-foot range. There is no way they are tangling in the stabilizer fins.

4. Drag from running both Fins + Fish would probably be cumulative. I ran a couple boats that had both, but only ran one at a time and didn't really keep track of the drag-effect anyway.

Not sure I agree having both fins and fish make sense. Not a bad thing, but I would probably make a choice. If the Loop is in your future, would definitely go with fins, but my guess is the dry-stack on the Nordhavn rules-out the Loop anyway.

Peter
 
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One OBS I forgot to mention is that a rope or wire pennant from the 'fish' to the surface vibrate when towed so use a smallish length of chain,which doesn't vibrate. Also I carefully measured my pennant length when the boat was in the yard to ensure the fish could never touch boat or prop.
When anchored the depth of the fish can be a couple of metres or more but obviously it should not touch the bottom or be able to break the surface when rolling..
 
There are several N40s with both. From what else is on them(SSB, watermaker etc.) looks like they were set up as passage making long range cruising boats. But defer to your experience and expertise. If we end up that way would probably use the fins as the go to and only the fish if the fins fail or to hang floppers. It’s been driven in to me by the more experienced and wiser people I know redundancy is a great thing on a boat. Particularly when your fallback is simpler. (No hydraulics, electronics or power needed). The loop is out unless the bride has an epiphany and says forget Nordhavn I want a KK. Personally not all that keen on the loop. Figure much the same as the ditch in places. For the parts of the ICW I would likely do I’ve done with 65’
 
The exhaust funnel / stack is a high point on the boat that can't be lowered, so depending on just how high it is, air draft could be an issue.

Exactly. Not sure what the air draft is on the N40 with dry stack, but it has to be more than 20-feet.
 
I bought a Selene 38 in Hong Kong as a retirement livaboard in Thailand etc. I anchored out almost all of the time due to lack of marinas. Consequently, after so research I built my own system of booms and "fish" The booms I fashioned from timber and a stainless fitting on the outboard end. The inboard end I used a spinnaker pole fitting which I attached to a large cleat that I bolted to two nylon clamp plates either side of the large rope bulwark hole. This provides a centre point for the pole and still provides a cleat for midship docking. The "fish are from a design seen in a yachting magazine some years ago and are a 500mm triangle with a tune in one corner filled with the lead from a dive weigh ie one kilo. This ensures the plates dive one the boat rolls towards the side they are deployed.
The system is usable underway and is very effective, although not used frequently. At anchor, one deployed is usually quit sufficient, two out are really good. I can deploy one in minutes and frequency do. The final 'fish" ended up being cut from 3/8 marine aluminium and the 'fin' was bolted at 90 degrees with pieces of right angles. Whilst this might sound like a "Heath Robinson" set up, I can assure readers that it is not and really looks and works very well. The original was fabricated in steel and painted to ensure it worked ok. When towed the (2) 'fish' reduce speed by 3/4 knot Towing one has been tried, is effective but needs 10degrees of wheel to counteract the drag on one side so not recommended. The poles, varnished, are 9foot long and suspended from the top of the short (strong/heavy) standard mast, They are raised/lowered with a simple block and pulley, and look 'fishing boat' Not to everyones taste/eye but having now travelled about 24,000 miles with them I'd be reluctant not have them. That said, a new owner, or I, could unbolt the lot in an hour and dispose of them to make the boat look tidy if required. They really work and have provided many many hours of comfort in rolly anchors in my travels in SE Asia and now Turkey.

Welcome to TF, Nightowl.

I'd love to see some pics of your setup. Sounds like a good practical system.
 
Hey Bob - these sound like the same design I have, which is same as Dashew shows at 18" x 24". He has 20-foot spinnaker poles to compensate for the smallish sized plates. Mine have a heavy plastic diaphragm vs the SS hinged gates.

That's the design I will eventually have using 2nd hand aluminium security screens like the below pic with 2 inch aluminium angle around the perimeter for additional support.
I have several sitting in a shed back at the dirt house doing nought.

s-l800.webp


Arms will be a h shaped arrangement to avoid fore and aft lines.
 
There are several N40s with both. From what else is on them(SSB, watermaker etc.) looks like they were set up as passage making long range cruising boats. But defer to your experience and expertise. If we end up that way would probably use the fins as the go to and only the fish if the fins fail or to hang floppers. It’s been driven in to me by the more experienced and wiser people I know redundancy is a great thing on a boat. Particularly when your fallback is simpler. (No hydraulics, electronics or power needed). The loop is out unless the bride has an epiphany and says forget Nordhavn I want a KK. Personally not all that keen on the loop. Figure much the same as the ditch in places. For the parts of the ICW I would likely do I’ve done with 65’

The buyer's of Nordhavn's tend to 'check all boxes.' I'm sure PAE does pretty well on add-ons alone. Buying one used means you often get a lot of value for the money, assuming you value stuff like two radars and $25k searchlights.

As a guy with a 36-foot trawler, all I can say is sooner or later, you run out of room for redundancy. I totally get the desire for a wing engine, but I think if I were that concerned, I'd go with a twin-engine setup like the Defever 44. The feathering prop on the Nordhavn wing engines isn't great - better than sail.

Hippo - if you haven't found Twisted Tree's blog site, spend some time on Adventures of Tanglewood. He had a N60 built, and is close to completing an N68 build. In a dual-act of near-heresy, he chose to (i) go with twins; and (ii) went with wet exhaust instead of dry stack. Why? I hate to put words in his mouth (especially since he's an extremely articulate writer), but if you read his early blogs, dry stack produces more heat which he had trouble evacuating on his N60; gear-driven water pumps are pretty reliable; he got tired of soot on his decks; and he preferred to have exhaust maintenance items inside the hull vs a keel-cooler. He makes a strong case and speaks from obvious experience.

My observation of Nordhavn owners is they seem to come in a few flavors: the newly-minted buyers (the check-the-box type) who are buying a dream and risk-mitigation. A large percentage take off and move on to something else in a few years, often grandkids or aging parents. They chose Nordhavn as a lifestyle brand - independence, globe girdling, 'the world is your oyster' type. They don't really know what they want, but they also don't know what they don't want so don't want any options cut-off from them. Thus the check-all-boxes. Great boat to buy second hand if you're okay with all the gizmos and doo-dads. In my experience, these bolt-ons often create their own ecosystem of support requiring larger/secondary generators, additional inverters, and all sorts of stuff that sometimes need specialized support only available at large yachting centers.

The second type of Nordhavn owner is the guy on MVDirona. I haven't watched many of his videos, but man.....the guy is a genius (I suspect Twisted Tree falls in this camp). These owners are simply not satisfied with 95% - they want 100% perfection. Often into their second or third 7-figure boat, they are super well educated on the systems and make well-informed decisions.

Of the first group, I wonder how many of these owners wash-out due to complexity of systems and constant support, and of course the expense. And I wonder how many of these complex yachts (of any brand - trawler or other) really go more than about 50 engine hours with everything working properly.

Long intro to say redundancy carries a cost. There's a difference between carrying spares and having redundancy, which is more or less hot-standby. It can be engaged without fuss. But you have to support both systems. Always. And provide the environmental, mechanical, and electrical support for both. That alone adds a lot of complexity so you end up spending a LOT of time on maintenance to avoid a possible inopportune breakdown.

Personally, I'd be careful carrying the redundancy maxim too far. It can be a trap that really distracts from cruising.

Peter
 
Thanks for the advice. Been cruising with one mast. One set of standing rigging. One engine . One of a lot of things. Did carry at least three spares of everything I could think of and tools. Tried and to continue to try to learn everything I can about every system aboard. As you can tell not afraid to ask questions nor be humbled. We’ve been successful so far. Average sailboat travels <1000 m per year. After 7 (with this one) we did at least 6-7k/year mostly with no marina nearby. Probably have equal miles before that. Always surprised when we screw up believing we’ve made every mistake you can when we make another. But we’ve muddled through.
If we do the N40 it will be heavier at 55k . The Outbound was 30k and kept on its lines. The Outbound actually had more storage then I found in the N40. It’s a small boat. In many respects smaller than the last one. Totally get what you’re saying and totally get two other things.
If you didn’t bring it with you .... you don’t have it.
You can’t buy safety nor a fail safe future.
You’ve been a great help to me. You’ve really clarified my thinking and have endorsed what I believe from experience and have been taught by others. Keep it coming.
BTW- wife and I like to travel. We have no bucket list. But do want the right tool for the job. Still not totally certain what that is. In spite of earlier comments that others find no enjoyment from it do like long hops and ocean transits. Not as experienced as many here and may have less blue water miles but at this point kind of know what we expect from a boat. Kind of feel like I do at an OCC meeting when you post. Jus soak it up and digest it.
Pursuant to your post. Don’t see a down side to having both. Get to choose which to deploy. Last boat was a new build. This one won’t be. Walk away thinking having both is a plus. Where am I wrong?
 
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Also at anchor is it ever a problem that a poled out floppier stopper entangles in a fin?

This has not been an issue for us, but our experience at anchor in an ocean swell is limited. That said, I think it would be extremely unlikely unless the fish don’t have enough water depth to hang properly. It’s nothing even near our list of concerns when anchored with the fish out.
 
Would note in this day and age nearly all cruising boats are complex. Next one will be equal or possibly less so.
Had SSB with modem and fleet one.
Whole boat filtration and RO
Solar and wind
Phillipi and dips and trhre ways to monitor all batteries and sources and two for ttanks.
Northernlights
Redundant nav systems
AP,and hydrovane
Reverse AC and wesbasto
The list goes on....
It isn’t a question if something will break it’s when.
Fully understand KISS. But you live on a boat you’re not camping out. So what you folks offer is priceless. You know what you really need, what’s good to have and what’s a waste of resources thats better applied elsewhere.
If I had Tanglewoods resources I’d build a Artnautica or Arksen or do a one off. Spent the last two weeks walking by Ha as we emptied our boat. Most impressive but we like to be mom and pop cruisers.
 
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Long intro to say redundancy carries a cost. There's a difference between carrying spares and having redundancy, which is more or less hot-standby. It can be engaged without fuss. But you have to support both systems. Always. And provide the environmental, mechanical, and electrical support for both. That alone adds a lot of complexity so you end up spending a LOT of time on maintenance to avoid a possible inopportune breakdown.

Personally, I'd be careful carrying the redundancy maxim too far. It can be a trap that really distracts from cruising.

Peter

I have not had the boat very long, but long enough to say this bit is an articulate, accurate, statement.
 
Figured I would give the Rocker Stoppers a go because they are easy to stow and cheap so if they didn’t work its not a big deal. I currently have 6 out on the Starb side with a 15 lb weight. They are definitely helping. I’’ll try another set on the Port side in the future and see how it goes.
 

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Has anyone tried something similar to a Jordan style series drogue? This is a line with small fabric parachute cones laced/sewn to the rope. It might take some length (and therefore more depth). The imagined advantages would be the weighted line would sink readily on the down roll, as the fabric parachutes collapse, also the storage space would be very small since the whole thing coils like a line, and retrieval easy. Imagined disadvantage would be the roll angle used up before the parachutes fill and resist. Would be mitigated a bit if on poles, not just for the leverage but for the velocity.

Curious if it has been tried, and the result.
 
Anything will provide some assist and dampening, but I doubt a Jordan drogue would be appropriate. I recently saw a used set for sale that had 135 cones. In addition to getting them to respond quickly, water depth would also be a problem

In the end, I think you have to decide whether your cruising grounds include open roadstead anchorages. If so, whether it's worth the time, trouble, and expense to create a proper solution which will involve either a gyro or outriggers with some sort of plates with fast-closing diaphragm or shutters.
 
"I think you have to decide whether your cruising grounds include open roadstead anchorages."

In places like St Barts folks simply use two anchors and point the boat into the constant swell .Folks seem to tolerate pitching easier than rolling.
 
When in St. Bart’s we just hung the dinghy on the side of the boat. Caused the boat to tilt slightly toward northern swell but got rid of most of the roll. This was on a high aspect bulbed fin keel which didn’t roll much to begin with. Also would set up our snubber bridle slightly asymmetrical to slightly face the swell. The two together eliminated roll. Conditions there are fairly constant. You get time to fool around to see what works best. There’s a fair amount of open roadsteads in the leewards/windwards. You pay attention to the presence or absence of northern swell. You choose where to anchor depending on that.
Thank you FF for reminding me which leads to a question.

Do trawler folks run a snubber to a midship cleat to position the boat to face the swell?
 
Do trawler folks run a snubber to a midship cleat to position the boat to face the swell?

I have done that on occasion and it has often worked well.

It worked when there was wind and it did not change direction.

When the wind dies the boat will settle in the worts possible position: perpendicular to the direction of the swells.

And if the wind shifts in relation to the swells one needs to readjust the spring.
 
"" Do trawler folks run a snubber to a midship cleat to position the boat to face the swell?
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Cant say , I visited with a 45 ft tri and with shallow draft (28inches) could use inner harbor.
 
Do trawler folks run a snubber to a midship cleat to position the boat to face the swell?

Shoot I've used one to turn the stern into the wind to get some cooling in the cockpit on a hot day.

Tips and tricks should be a category somewhere on here.
 
Anything will provide some assist and dampening, but I doubt a Jordan drogue would be appropriate. I recently saw a used set for sale that had 135 cones. In addition to getting them to respond quickly, water depth would also be a problem
.

Well a 135 cone drogue is intended to nearly stop a 45' boat in 50 knots and fully developed seaway with an expected drag of several thousand pounds. The area of just 5 or 6 cones is similar to many of these flopper stopper type devices. Most of these things have some hysteresis: flaps or shutters have to close, wings unfold, or whatever. So I'd not dismiss it out of hand. Looks like an experiment I'll have to try myself.
 
Well a 135 cone drogue is intended to nearly stop a 45' boat in 50 knots and fully developed seaway with an expected drag of several thousand pounds. The area of just 5 or 6 cones is similar to many of these flopper stopper type devices. Most of these things have some hysteresis: flaps or shutters have to close, wings unfold, or whatever. So I'd not dismiss it out of hand. Looks like an experiment I'll have to try myself.

From my experience with my 'plates,' there are two factors that make a flopper stopper successful. First, it must descend freely and quickly. Second, it must quickly transform from easy free-fall to substantially resist ascent. This must happen within a couple feet of travel, and it must happen in waters that are often less than 15-feet. I just don't see how the loose-fabric Jordan drogue would be effective, especially since the Davis "Mexican Hats" are a similar concept and provide marginal dampening at best.

But if I had a Jordan Drogue, I'd give it a try. At least to see how they open and close.

Peter
 
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