Stabilizers?

[angus99]

Even if they need an aftermarket device added to make it more sea kindly and comfortably after its been designed and built ? You don't see that as a flaw?

Its like buying a new car that gets out of shape going into every corner but if you take it to the suspension shop and throw some more money at it the problem gets sorted.
It should have been done at design stage and done before it left the factory.

George answered your question better than I could. I’ll just add that Art’s recreational designs were based on hulls he drew up for the offshore tuna fleets (before active fins were on the market). Don’t think those guys were known to squander money on flawed designs.

Rolling in a beam sea used to be the price you paid for a safe, fuel-efficient displacement hull. Technology advances and what may have been considered an annoyance or weather-limited feature of the earlier designs can now be compensated for.

I think a more accurate car analogy might be a classic from the 70s or 80s. While restoring a TR6, I added numerous upgrades that didn’t exist when the car was built. But I’d Hardly call it a flawed design (except for the Lucas electrics).

 

[Simi 60]

I guess what I am saying is if these hulls, and I include ours in the mix, were perfect, they would not need expensive bolt on appendages to make them better.

If rolling chocks are proven to make a hull less rolly, surely a more streamlined and structural version of rolling chocks could be designed into the hull at build stage instead of being tacked on as an afterthought trying to remedy a problem that is known to exist.

Thinking like a keel on a sailing yacht or dagger boards on a catamaran.
They don't get built and launched and then have someone go, "gee, I reckon this would be better with a keel or a dagger board", it gets thought about, drawn in and built in before it hits the water..

 

[catalinajack]

Ray,
I totally agree with you active stabilizers do a good job when working.
They are high maintenance items, and have a very high failure rate when you need them the most.

High failure rate? I have owned a stabilized DeFever 44 for more than five years and have cruised extensively. No maintenance has been done and still they are working just fine. I wouldn't leave home without them. Just one boater's experience.

 

[catalinajack]

A little spendy up front but maintenance is fairly easy and not very expensive when a line or winch needs to be repaired/replaced.



I plan on a steadying sail while I do the loop. It's the cheapest easiest solution for me and my initial Great Loop plans. Then I may consider paravanes for the Inside Passage.

Steadying sail doing the Loop? Make certain your boom will clear the lowest bridge you will encounter.

 

[mikecurreri]

After 55,000 NM in a Selene 55 at 8 knots (including the Bahamas and the Down East Loop) and a Marlow 70 at 11-16 knots, our stabilizers never failed and were often critical and always otherwise welcome. I wouldn’t cruise without them. I recently took a Sabre Express 45 out for a spin with a SeaKeeper 6 installed. It was rock solid.

 

[lipets]

I plan on a steadying sail while I do the loop. It's the cheapest easiest solution for me and my initial Great Loop plans..

also some designs just hide the sail behind cabins ir bridges surround in canvas blocking any effective wind

More recently sails are being made with flat heads or fat heads where upto 40% of the boom length is added to the top of the sail
this adds about 25% to the sail area.

Kinda interesting

 

[caltexflanc]

I guess what I am saying is if these hulls, and I include ours in the mix, were perfect, they would not need expensive bolt on appendages to make them better.

If rolling chocks are proven to make a hull less rolly, surely a more streamlined and structural version of rolling chocks could be designed into the hull at build stage instead of being tacked on as an afterthought trying to remedy a problem that is known to exist.

Thinking like a keel on a sailing yacht or dagger boards on a catamaran.
They don't get built and launched and then have someone go, "gee, I reckon this would be better with a keel or a dagger board", it gets thought about, drawn in and built in before it hits the water..

And keels are built into a lot of motorboats too. Visit a boatyard sometime. Most all of a sailboat's stability comes from the sails, not the keel. Observe a sailboat without its sails up in a beam sea (an amazingly common occurrence here). Tolling chocks do not mitigate roll nearly as effectively as other forms of stabilization... and induce additional drag moreso, being more substantial than say active fins, which are smaller. As the old truism goes, all boats are a compromise.

 

[Ejdakins]

Well I am not sure, I have always enjoyed the fresh air and some times the sea spray at placing the birds in the water, seem to me to be a bit more enjoyable than pushing a $75,000.00 button, to achieve the same effect.

 

[caltexflanc]

Well I am not sure, I have always enjoyed the fresh air and some times the sea spray at placing the birds in the water, seem to me to be a bit more enjoyable than pushing a $75,000.00 button, to achieve the same effect.

Why not just get a sailboat then? Always out in fresh air, plenty of spray and cheaper still.

 

[PopeyeGB36]

I'm sure other will disagree with you - especially those that are prone to seasickness. But man has been going to sea since before recorded history existed. And the boats that early man used weren't as sea kindly as our new fiberglass hulls that are hydrodynamically designed for efficiency and as decent a ride as you can get on the ocean.



Since I love boats so much I thank my lucky stars that I'm not prone to seasickness. I think I had me sea legs when I was in diapers.

 

[Fletcher500]

[/FONT][FONT=&quot][/FONT]
[FONT=&quot]Here in the Baltic Sea West we have a wave period of 4 seconds at 3-4 ft, 3 seconds at 2 ft, because of the shallow water. A wave periode of 8 seconds I would call comfortable
[/FONT][/QUOTE]

I never said it was uncomfortable. I was simply pointing out the conditions of the previous week, and noting that is was more comfortable with the stabilizers on after a long day of fishing. Not a competition, just another day on the water.

BTW, we were the first Helmsman to get a Gyro. The builder (Scott) asked to me write a brief article for his website last year. Its on his website under Trawler Talk if anyone is interested. It's not very technical, just my impressions.

 

[ben2go]

I've written extensively about this before, so I'm not going to repeat myself too much.
I'll only add this:

Without paravanes, I've been up and down the East Coast from Florida to New England and Nova Scotia, back to Florida and the Bahamas, then Florida.
I had to tack at times roo keep the seas off the beam. We stil rolled a lot, but it wasn't terrible.

Finally had the paravanes stabilizers installed in Florida. Cost about $9k.
5 years later, I'm still so happy. Could not have crossed the ocean without them.

But for coastal cruising, ...

I'm too adventurous for hydraulic fins. I need the protection from the nut behind the wheel that a full keel provides.

If you love the boat so much, the investment seems worthwhile. In any case, you can try without for a while.

Thanks for tuning in. I hope your travels are going well. Good to hear everything is still working well with your set up. I may consider them when I move over to the west coast. I don't think I'll need them for the Great Loop.

 

[ben2go]

Steadying sail doing the Loop? Make certain your boom will clear the lowest bridge you will encounter.

The stick will be mounted in a tabernacle and will fold forward into a stand on deck.

also some designs just hide the sail behind cabins ir bridges surround in canvas blocking any effective wind

More recently sails are being made with flat heads or fat heads where upto 40% of the boom length is added to the top of the sail
this adds about 25% to the sail area.

Kinda interesting

If I fit a steading sail, it will be just above the rear of the cabin. With an air draft, less mast, of seven feet, it's hard to put a mast on my boat.

 

[Cartouche]

We are on the great lakes at the end of Lake Ontario, you need stabilizers to travel the lake or it gets real lumpy, we do not have them and are moving our boat off the lake

 

[cardude01]

The stick will be mounted in a tabernacle and will fold forward into a stand on deck.





If I fit a steading sail, it will be just above the rear of the cabin. With an air draft, less mast, of seven feet, it's hard to put a mast on my boat.

I don’t think a small steadying sail like that will stabilize a boat that size. I need all of my 370 sq feet of sail on my much smaller boat to steady the rolling, and I need winds over 10 knots.

 

[balder8]

If you're considering retro fitting active fin stabilizers, I can recommend Keypower, owned by Kobelt, a highly regarded Canadian manufacturer of commercial hydraulic steering and power systems. Keypower active fins use dual piston actuators, reducing the work they do by 50%, the fins are made from a polyurethane material producing near neutral buoyancy in the water and connect to the actuators with a keyless tampered shaft (super easy to remove and remount), and like everyone else, the fins are controlled by a digital gyro control box that gets mounted tighter up in the pilothouse (for early motion detection). I bought mine direct from Kobelt for a significant discount from what other stabilizer makers had quoted me. So far, no problems.

I agree with you, far from East or West coast - I am currently in Europe- I have had a very friendly and professional support from Mr Yule, founder of Keypower to do some repair on my stabilizers in Gibraltar where one of my solenoid valves failed. ( they have been installed ten years ago)
I recommand as well this Canadian company.

 

[Mako]

Give an idea of how much they cost. Thanks

 

[FF]

I have 2 sets of paravanes for sale if interested PM and I will post them in the for sale section.


Located near the Ortona lock in FL for pickup.

 

[mvweebles]

I am in the process of having my old Vosper stabilizers replaced on my Willard 36. I chose Wesmar because their smallest system is appropriate for my boat. I had not heard of Kobelt prior to reading this thread a few minutes ago, and I wish I had - I have had lousy tech support from Wesmar despite spending $22k for the stabilizer system. They have been unable to answer simple questions such as what is the system amp-draw, and can a certain cable that connects the display to one of the large black-box brains be extended from it's current absurdly short 1-foot length. Wesmar has a good reputation from years back, but on reflection, the new generation of digital-controlled stabilizers may have changed Wesmar. Hopefully, my initial experience will be eclipsed by years of trouble-free service. But right now, I am really sorry I chose Wesmar.

 

[sunchaser]

I am in the process of having my old Vosper stabilizers replaced on my Willard 36. I chose Wesmar because their smallest system is appropriate for my boat. I had not heard of Kobelt prior to reading this thread a few minutes ago, and I wish I had - I have had lousy tech support from Wesmar despite spending $22k for the stabilizer system. They have been unable to answer simple questions such as what is the system amp-draw, and can a certain cable that connects the display to one of the large black-box brains be extended from it's current absurdly short 1-foot length. Wesmar has a good reputation from years back, but on reflection, the new generation of digital-controlled stabilizers may have changed Wesmar. Hopefully, my initial experience will be eclipsed by years of trouble-free service. But right now, I am really sorry I chose Wesmar.

The success or failure of different types of complicated mechanical and instrumented installs is largely dependent upon the capability of the technicians, users and designers. I could point you towards other brands of active stabilizers where a less than stellar install and technician prowess let the otherwise good stabilizer name down. A common point of failure is cooling with many solo installers and well known builders missing the mark on this, especially dry stack vessels.

Stabilizers are not an addition or retrofit where plug and play succeeds. Good luck and hopefully this issue will be smooth sailing and well managed from here on.

 

[mvweebles]

Stabilizers are not an addition or retrofit where plug and play succeeds. Good luck and hopefully this issue will be smooth sailing and well managed from here on.

I agree that adding new stabilizers is not a plug-play item - they must be sized and the hull adequately reinforced, which requires engineering. As mentioned in the original post, the boat had Vosper stabilizers installed when the boat was built in 1970. I still have blueprint drawings of the engineered installation from Vosper Thorneycroft specifically for this vessel. The replacement Wesmar system is similarly sized as the old Vosper system.

I believe it reasonable to expect the OEM (Wesmar) to (i) respond to technical questions in a timely manner; and (ii) be able to provide basic system information about their equipment, such as power requirements and whether a certain cable can be extended (the manual clearly states that some cables can be extended, others cannot be without contacting Wesmar - and is silent on this particular cable). All I can tell you is my experience with their customer service was fine in the sales process, but awful after the check was cashed. They have been mishmash of conflicting or ambiguous information, or dead silent.

I will add one final comment - installing the new Stabilizers is not a trivial item mechanically, even when replacing an existing set of similarly sized stabilizers. However, electrically, it is damn close to plug-and-play. There is a display panel, two black-boxes, and a gyro. They all come pre-wired with can't-screw-up plugs. All you have to do is hook-up to power. Too bad Wesmar doesn't know (or won't tell) how much they need (I eventually found a tech who could confirm 7A @ 24V, and use of a step-up transformer was fine versus original Wesmar recommendation to install two 12V 100AH batteries and a 24V charger, the typical approach for a 24v thruster but massive overkill for this application).

 

[long-cours.62]

Our former Long-cours.62

was relatively narrow (L/B at wl 4.19) with low cg...low cg could be good for the
"capsizing angle" but the roll period at the beginning was around 2"...
Later in "navigation" configuration with rigid tender on the roof, solar panels, mast...the roll period increase little.
When we design the structure and deck it was for fit a mast.
Mâture - Trawler long-cours



with sail, dagger board down

Dérives - Trawler long-cours


the motion was more comfortable and later we fit to small "bilge keel" (4000x240) .


One of the problem with active fin : they are exposed if you want go on river or/and canals, icy place it is better to remove them...(you already said about maintenance and price).
Gyroscopics model could be a solution, but when we ask for a quotation at Sea.... they said you need this model at 70000$us but with the great stability of your boat it will be better to fit ...TWO for 140000$us

My stomach stop complain when he facing my bank account

Now an Italian company make cheaper gyroscopic model but I don't ask for quotation.

 

[sunchaser]

Even if they need an aftermarket device added to make it more sea kindly and comfortably after its been designed and built ? You don't see that as a flaw?

Planing vessels generally work great without stabilizers. Run them slow in heavy beam seas and voila, planing vessels become uncomfortable. The addition of stabilizers, such as a Seakeeper, to larger outboard powered vessels is now becoming common. The buyers are voting. Stabilizers of some sort are becoming as common as adaptive cruise control. Try it once and you'll not go back.

Builders and designers are in the business to sell boats. Comfort sells in virtually 100% of the the new build cases where boats are used offshore. Many a vessel in Angus's list was built without some means of stabilization. Sure they were seaworthy, just not comfortable. Thus not easily saleable.These non stabilized "trawler" vessels were either stalking horses for later stabilized designs or altered with some means of stabilization.

Without roll mitigation or stabilizers, where would the cruise ship business be? Comfort sells.

 

[Stickman]

You need them if your mate(s) won’t travel with you after their first adverse experience rolling without stabilizers on a round bottom boat.
My first mate/admiral keeps them on for boat wakes in the harbor or ICW. But then she feels well and happy to continue on the boat.

Careful to have installation performed in a manner that facilitates FUTURE service access.
Don’t forget that!

 

[mvweebles]

You need them if your mate(s) won’t travel with you after their first adverse experience rolling without stabilizers on a round bottom boat.
My first mate/admiral keeps them on for boat wakes in the harbor or ICW. But then she feels well and happy to continue on the boat.

Careful to have installation performed in a manner that facilitates FUTURE service access.
Don’t forget that!

In open water for long passages and long term cruising, some form of stabilization is in the "must have" category for me, and certainly my mate. If I couldn't afford it, it strongly consider a sailboat instead of power. But there are many ways to stabilize.

Here are all the options I can reasonably think of for a long distance trawler. Educated guestimates for a 42-ish foot boat.

Active hydraulic fins. $40k-$50k. Instant on and usable for oncoming boat wakes. Main drawback is cost. They can break if you hit an obstruction, but this is rare. For at- anchor, desirable to add some sort of flopper stoppper setup. Slight drag even when not running. Probably another $3k

Paravanes - $10k-15k assuming adequate structure. Near-instant on/off. Main drawback is width - if you spend anytime in crab trap waters, you will hook one eventually. Can't run in ICW for boat wakes, and can be a bit awkward to set. Works well at anchor. No drag when not deployed. Requires significant maintenance every 5-8 years at haul out. Also requires flopper stoppers at anchor.

Gyro. Works well at anchor and underway. Expensive - in the $60k range, heavy, and takes a lot of space - size of a generator. It takes 120vac full time and is a fairly significant draw. No underwater appendages. Good for boats that run generators full time anyway.

Roll Chocks. Fixed longitudinal fins on bilges of boat, probably in range of 12-feet x 8-inches off hull. Adds slight drag at all times. Several Willards have these and owners report they reduce roll significantly. About $12k at a yard. Still need flopper stopper for at anchor.

Steadying sail of under 75sf. Not effective in most conditions (I have had two boats with steadying sails - took half a hurricane on the beam to "set" the boat). Under $1k if you already have a mast.

Large sail rig such as those on Diesel Ducks. Probably a $20k add-on. Also serves as get-home or get-somewhere power. Can be pretty effective. Main disadvantage is it cannot be retrofitted unless boat was originally built to accommodate, and not practical for Loop. No additional underwater appendices.

Other. I've heard of large tanks filled at a high location but know nothing of them. Also, would be remiss if I didn't mention form-stability of a power cat. I've been aboard a 2014 Horizon 52 Power Cat for about 800 nms over a few trips. Great at anchor. Underway, movement is a bit choppy for my tastes. The purpose built long distance power cats such as those popular in Australia may be better (Malcolm Tennant designs come to kind, but I have no personal knowledge)

 

[Simi 60]

.

Without roll mitigation or stabilizers, where would the cruise ship business be? Comfort sells.

Doing things like this?

This one from Incat Crowther is 130 meres

https://www.incat.com.au/the-worlds-largest-aluminium-ship/

 

[AusCan]

I don’t think a small steadying sail like that will stabilize a boat that size. I need all of my 370 sq feet of sail on my much smaller boat to steady the rolling, and I need winds over 10 knots.

View attachment 91381

I’d agree. More sail area is required.

Another point to remember - A full displacement round bilge hull will be more tender and rolly in a beam sea, but they also benefit more from any type of stabilizer system. A hard chined boat requires a bigger sail/ gyro/ active fin/ paravane system to get the same benefit as a smaller system on a FD boat. Full displacement boat are easy to roll any easy to stop rolling.

 

[hjorgan]

If you have never experienced the Seakeeper gyro stabilization it is worth it to visit the demo boat at your favorite boat show. The demo boat we saw was a Contender center console.

They put 3 of us on each side of the boat, gripping the t-top and standing on the gunwales. The guy said "rock it hard as you can" and we did, because we all were pretty beefy. We were almost taking on water from the roll. Then he hit the switch and it was like that boat had hardened in concrete. Try as we might, we couldn't get more than a 3 inch roll.

This model was the light model for small boats, and yes, it's about 30k. For a large trawler probably 60k. Expensive yes, but it does the job for sure.

 

[Mako]

Yet they installed two (2) Seakeeper gyros on the Nordy 63 I visited at the Annapolis boat show. $120,000. Guy said it was a huge waste of money. So perhaps they are not ideal for all applications.

 

[mvweebles]

Re: comment on displacement hulls being more tender and rolly. As an ex-delivery skipper along the pacific coast, I have 1000s of offshore miles on displacement hulls from Nordhavn, KK, Selene, and Willard. Without stabilization, the boats are a bit tender for first 10-15 degrees, then start to stiffen. The lower the A/B ratio (more accurately, lower weight aloft) and the higher the ballast ratio, the more comfortable the roll period. Stiffness isn't always a positive thing - the most stabile/stiff hull form is a catamaran. Many find them uncomfortable in beam seas due to very sharp movements. While I have only done a couple offshore trips in a power cat, I understand that sentiment, but in short, sailboats do best in a beam sea so any discussion on power boats is degrees of roll mitigation, nothing is really great.

In my opinion, Bill Garden got it right when he designed the Willard 36 back in the 1950s. But it's a very small boat and not suitable to most except Sailors. One of my most memorable days offshore was off the central California coast aboard our Willard 36. We were running south with a 12-foot swell running from WNW at about 15-seconds. Boat gently rolled through 10-degrees in a slow period and we felt no reason to turn on the stabilizers. It was a magical run.