which stabilizers for us?

I looked at the Mitsubishi gyro when it first came out and rejected it on the basis of less effective damping and the need to run the genset most of the time. Ended up with Trac stabilizers from ABT. Offshore on the West side of Vancouver Is you can leave your Sonicare stood up in the head and it doesn't fall over when underway in the slop. Delfin has rounded bilges and the positioning of the fins is ideal so the results with your underbody may be different, but for us, the effectiveness is amazing. ABT is highly recommended so I would definitely get a quote from them. I can't prove it but I think my fuel economy is positively affected by stabilization because it keeps the hull square in the water where it presents the least drag. Since I can detect no change in speed with the fins off I assume they create little drag when on.

The only time we have wished for zero speed stabilization is like you, when drift fishing. Doesn't seem like a big enough problem to solve, at least to us.

Hope that helps...

Carl Martin said:

Have you considered a flume tank? I pulled this off of a Boat Design thread. I haven't been on the T&T forum in some years but the owner of this boat used to post there & I remember him being very happy with the results under power & at anchor.

"One example of the Flume Tank that apparently works was designed by Professor Don Bass of St. John's Newfoundland. This tank was mounted on a motoryacht called Swan Song, a Roughwater 58' designed by Edwin Monk. The rectangular tank is on top of the pilothouse, and is 12' long (athwartships), 4' fore and aft, and 16" high. Inside are 5 T-shaped baffles !8" from either end. The tank reportedly weighs 250 pounds (foam-cored glass) and has 1550 pounds of water in it, about 6.5" deep when floating level. The owner it totally tickled with it. Zero maintenance, zero drag, but of course real concern about high-angle stability and a simple system to dump the weight if needed."

Click to expand...

It called Anti Rolling Tank, ART for short. The Swan Song crossed the Pacific to Hawaii where the boat is for sail. We have a sister boat, 58 ft Roughwater, and I have the designs for the ART as we have email several times over the years. The principle is the same of the bilge flume which are more known.

Not many people know about ART and/or twin bilge keels so discussion/information is limited. They are both relatively cheap, easy to install, require not energy and are passive. However, ART does not solve my primary concern of preventing the Eagle from rolling over when grounded/hard/grid.

I agree a sea anchor will keep the bow into the wind/waves reducing the beem roll. The Swan Song used a sea anchor when they had to stop the engine to chnage oil and servcie. We have one but have not used it. It also could be dragged a stern to slow the speed for trolling.

There's alot to be said for passive systems. Always better than active IMHO provided they can get the job done.

I would also get a demo of a gyro in the large swells you are operating in - not with the wake-generated activity I've seen in the demos on the gyro sites.

And I'd really suggest thinking about another boat for fishing <grin> I saw a large OA in Vancouver with a RIB like mine with dual outriggers. I've also seen a number of motoryachts towing fishing boats. How about you leave your wife comfortably protected at anchor on the mothership while you blast off in a fishing machine for a few hours?

How about you leave your wife comfortably protected at anchor on the mothership while you blast off in a fishing machine for a few hours?[/QUOTE]

Now that is an idea. For $47,000 You could get one heck of a fishing boat.

Or does the wife like to fish?

SD

I have Wesmar fin type stabilizers in my Offshore 54' and they are amazingly effective when under power. I have been out in 10' rolling seas recently and when the stabilizers were switched on the difference was amazing. They are only 4.5 sq ft each and of course they don't do anything at anchor. However, having spent years in PWS and Resolution Bay areas of AK on a round chined 40' trawler, I never once had to anchor up in an uncomfortable rolling anchorage. Also, the Wesmar is hydraulic and runs off a PTO on one engine. Very effective and low energy needs combination. Just my 2 cents. Good luck!

As usual I'm getting ito this late in the game

Having experience with the 47 and now the 48 with active stabilizers I have some thoughts.
Any added weight in the stern of your 47 will effect your speed and trim angle. Another 750Lb plus your genny and battery bank will effect performance drastically. So on that basis alone I would rule out the gyro. Weight is your enemy on the 47. In fact I think that much added weight may cause you to move your boot line up and cause your cockpit drains to be at water line or slightly below. So you would probably need to add sea cocks to these drains. I know this can be a problem as my boat had the 12kw genny and combined with the four L16 batteries and my 2-8D starting batteries this is what I had to do.
You have round chines but a very flat hull and this is the cause of your pitching. The 47 has a very low center of gravity so the pitching has more to do with it's flat hull than anything else.
As you mentioned once you get the 47 semi planing this is not an issue, it's only drifting when the boat swings beam to the swell or chop. Since I fought with this same issue with mine I considered para-vanes and decided as you have that it just doesn't fit the look or purpose of the boat.
There have been several 4788 that were fitted with stabilizers and there must be something in the Bayliner forum discussing them. The relative light weight of the 47 makes me think that 6sq' or smaller fins might be able to over power the flat hull shape and give you the relief your looking for. They work wonders on the relatively round bottom shape of the 48LRC. If you think about it you have probably 400 sq' of flat hull to over power. So I'm not sure at drifting speed the fins are going to be that effective. They would certainly help. On plane they would control all roll and I think in a following sea they would improve directional control maybe even eliminating the 47's tendency to broach when surfing. If they do this would be well worth the cost.
The machinery to run the fins takes up a lot of space and that may create issues in a already tight engine room. they are also driven by one engine and if you wanted to drift that engine will be getting a lot of idle time the other engine isn't. I guess you could drive them off your genny but I think your using a 8kw now and it might not have enough reserve hp to run the pump for the stabilizers. Fins also create drag and will effect your cruise speed and economy. Still they may be the option that makes the most sense.
Here's a thought I think might be worth trying. You could install a couple of short out riggers just behind the pilot house off the gunnel and deploy flopper stoppers the mushroom shaped type that slide up and down dampening roll. You can add as many as you need to create the dampening needed and this would be fairly easy to deploy could be stored in a deck box when not needed and would except when deployed have no effect on your boats appearance. Some short guy wire and a bracket on the butt end of the out riggers would be all that would be needed. I've talked to boaters using them on Grand Banks who swear by them. If I had kept my 47 this was what I was going to do. This snap roll and tendency to broach were the only issues I had with 47, if active stabilizers fix this you'll have the near perfect boat.

Scary said:

Having experience with the 47 and now the 48 with active stabilizers I have some thoughts.
Any added weight in the stern of your 47 will effect your speed and trim angle. Another 750Lb plus your genny and battery bank will effect performance drastically. So on that basis alone I would rule out the gyro. Weight is your enemy on the 47. In fact I think that much added weight may cause you to move your boot line up and cause your cockpit drains to be at water line or slightly below. So you would probably need to add sea cocks to these drains. I know this can be a problem as my boat had the 12kw genny and combined with the four L16 batteries and my 2-8D starting batteries this is what I had to do.
You have round chines but a very flat hull and this is the cause of your pitching. The 47 has a very low center of gravity so the pitching has more to do with it's flat hull than anything else.
As you mentioned once you get the 47 semi planing this is not an issue, it's only drifting when the boat swings beam to the swell or chop. Since I fought with this same issue with mine I considered para-vanes and decided as you have that it just doesn't fit the look or purpose of the boat.
There have been several 4788 that were fitted with stabilizers and there must be something in the Bayliner forum discussing them. The relative light weight of the 47 makes me think that 6sq' or smaller fins might be able to over power the flat hull shape and give you the relief your looking for. They work wonders on the relatively round bottom shape of the 48LRC. If you think about it you have probably 400 sq' of flat hull to over power. So I'm not sure at drifting speed the fins are going to be that effective. They would certainly help. On plane they would control all roll and I think in a following sea they would improve directional control maybe even eliminating the 47's tendency to broach when surfing. If they do this would be well worth the cost.
The machinery to run the fins takes up a lot of space and that may create issues in a already tight engine room. they are also driven by one engine and if you wanted to drift that engine will be getting a lot of idle time the other engine isn't. I guess you could drive them off your genny but I think your using a 8kw now and it might not have enough reserve hp to run the pump for the stabilizers. Fins also create drag and will effect your cruise speed and economy. Still they may be the option that makes the most sense.
Here's a thought I think might be worth trying. You could install a couple of short out riggers just behind the pilot house off the gunnel and deploy flopper stoppers the mushroom shaped type that slide up and down dampening roll. You can add as many as you need to create the dampening needed and this would be fairly easy to deploy could be stored in a deck box when not needed and would except when deployed have no effect on your boats appearance. Some short guy wire and a bracket on the butt end of the out riggers would be all that would be needed. I've talked to boaters using them on Grand Banks who swear by them. If I had kept my 47 this was what I was going to do. This snap roll and tendency to broach were the only issues I had with 47, if active stabilizers fix this you'll have the near perfect boat.

Click to expand...

Thanks Steve

I remember talking with you regarding my concerns with rolling prior to buying the 4788. As you can see, they've come to fruition.

Naiad recommended 6 sqft fins based on a 9 knot cruise speed, and the rep being familiar with the hull grometry of the 4788.

The components of the current generation Naiad gear are a control box that we'd mount in the engine room on the port side, either on the foward bulkhead or outboard of the port engine, hydraulics, and fins.

The hydraulic pump setup can be either electric or engine mounted. I think engine mounted would be best, plus a reservoir for hydraulic fluid. I'm checking on the electrical requirements as a option, to see if a good size inverter could handle the load. If i chose electrical they have a power pack that is a complete system with electrical and hydraulic hose connections.

The fins will/would be located either under the mid or bunk stateroom berth for port and either the mid or master head sink cabinet for starboard. They require an 18" sq backer plate to be installed to distribute the loads.

At this point I'm quickly discounting the Gyro not only because of the weight, but because they cannot document any installations of a similar boat to mine.

On the other hand the Naiad rep would be happy to take me out for a demo cruise on a similar size semi displacement boat to show me just how well the fins work. He invited me to come down, and indicated that once I've been on a boat with fins I'd never own a boat with out them.

Here's an interesting thread about a guy with a GB47 Europa who installed ABT Trac stabilizers himself:
Stabilizer Installation - Cruisers & Sailing Forums

Bottom line: He still spent about $12K to install them (and 100+ hours of his time) versus the $25K to $30K quoted by installers.

Anyone considering installing stabilizers would do well to read this thread - it is not a plug and play process!

refugio said:

Here's an interesting thread about a guy with a GB47 Europa who installed ABT Trac stabilizers himself:
Stabilizer Installation - Cruisers & Sailing Forums

Bottom line: He still spent about $12K to install them (and 100+ hours of his time) versus the $25K to $30K quoted by installers.

Anyone considering installing stabilizers would do well to read this thread - it is not a plug and play process!

Click to expand...

Thanks!!!!!

What a wonderful thread!

I have been debating that approach!

I could do that job (except the fiberglass)

My background is that of an electrical, electronic, and mechanical technician/ quasi engineer.

I'm going to really think about the labor on this. I have installation details from the exact same boat as mine, so the structural engineering is complete. I could hire a good fiberglass shop to do the build up then do the rest myself.

That's something to consider.

Everything but the fiberglass is well within my existing skill set.

Interesting!!!!!

Perhaps you could hire out just the fiberglass work?

We've been looking at this also, since we have a high-capacity engine-driven hydraulic system already in place. The weight of the actuators is quite significant. In the case of the Side-Power system, which seems to have a few advantages over the other brands, 230lb per side. These actuators are the most compact but very heavy. Just another consideration....

An obvious consideration for active fin stabilizers is their position. While this is totally in the hands of the skipper and not a drawback to the fins themselves, there have been occasions when a fin was ripped off on a rock or other obstruction. The most recent case I've heard about was during a Puget Sound-SE Alaska Grand Banks-sponsored cruise a few years ago. One of the participating boats was a GB66, a boat that in my and a lot of other people's opinions should never have been made. GB made three of them and then I guess realized their mistake and didn't make anymore. The reasons are not for this particular thread.

But during this cruise the GB66 got too close to a rock or reef either entering or leaving an anchorage, tore off one of the large fin stabilizers and the resulting hole and ingress of water threatened to sink the boat. Only the fast action of a very experienced GB rep and shipwright (IIRC) saved the day.

The moral here is not "don't use active fin stabilizers" but "don't hit anything with them." Not as much an issue I would imagine in open water or places like the Gulf or eastern seaboard, but perhaps something to keep in mind in the narrow, rocky passes and entrances we can get around here and up into BC and Alaska where the water can go from real deep to rocks in a boat length or so.

Hitting something is almost always a helmsman issue, not a boat configuration issue, but depending on where one boats having a fin projecting down and out from each side of the hull can be one more thing that's important not to forget about.

Marin said:

Perhaps you could hire out just the fiberglass work?

Click to expand...

Thats what I'm thinking about. Then doing the rest myself.

I'm going to get a quote from the Trac folks. So far I've only really investigated Naiad.

The Naiad rep sent me a fin placement document that I'm going to look over. That said, I have detailed photos available of a Wesmar fin installation on a 4788 Bayliner. This installation did not require any moving of stringers or other complicated rework. It involved a large build up area in an existing compartment.

This corresponds to what the Naiad rep told me which is that in order to spread out the load Naiad recommends a 18"X18" 1.5" hull build up. That does not sound too awful complicated. I think a competent fiberglass shop should be able to do that.

The other components of a stabilizer system are:

Hydraulic. This involves mounting a hydraulic pump to either the engine or transmission. There a reservoir, cooler, and hoses to the fin actuators.

Mounting the fin actuators is really not that difficult sounding. Drill a hole, or holes. Sandwhich the pieces together.

Mount and cable the control box to the fins, power, and any other signals it needs such as the helm control, transmission reverse sensor, etc...

When you break it down, this really does not sound all that complicated.

The Ted Geary designed Malibu tore off a stablizer and sank (onto a reef) a few years ago in the San Juans. $2.4mm to repair:
Antique Boat World - The Ultimate Community for Wooden Boat Owners - Chris Craft, Garwood, Hackercraft, Shepherd, Century, Peterborough, Lakefield

ksanders said:

Thanks!!!!!

What a wonderful thread!

I have been debating that approach!

I could do that job (except the fiberglass)

My background is that of an electrical, electronic, and mechanical technician/ quasi engineer.

I'm going to really think about the labor on this. I have installation details from the exact same boat as mine, so the structural engineering is complete. I could hire a good fiberglass shop to do the build up then do the rest myself.

That's something to consider.

Everything but the fiberglass is well within my existing skill set.

Interesting!!!!!

Click to expand...

If you are handy...and it sounds like you are...fiberglass/epoxy is pretty simple/forgiving.

I have Niads

I was just down at Marine services in Stockton Ca and a 4588 was on the hard.I don't think the 45/4788 is as flat as my memory thought. I think going with active stabilizers will make a hell of a lot of sense. I say go for it. They make an huge improvement on the 48 LRC. I think I would go all hydraulic as it's probably more reliable. Mine are angled so as to not project beyond the gunnel. I think they improve tracking down wind immensely. Sounds like a worthwhile project.

Why not compressed air? These guys have my attention and I am considering this for Skinny Dippin'. I think for you, a 4-fin system would work well. Easy install, small footprint, lower pressures, cleaner (no oil spills), and I would bet a damn-site cheaper.

Gyro Gale Stabilizers

Tom-

While the GRP is easy to do , the increased thickness must be properly engineered/

Just a 1 1/2 thick section added to the hull will probably create a square hole if contacting anything.

The pad must be properly tapered to not create a hard spot in the hull if it is to stay in place.

So a 2 ft square pad may require clearing and grinding a 3 ft section of the hull for proper bonding.

I would spring for epoxy resin for the internal reinforcement.

FF said:

While the GRP is easy to do , the increased thickness must be properly engineered/

Just a 1 1/2 thick section added to the hull will probably create a square hole if contacting anything.

The pad must be properly tapered to not create a hard spot in the hull if it is to stay in place.

So a 2 ft square pad may require clearing and grinding a 3 ft section of the hull for proper bonding.

I would spring for epoxy resin for the internal reinforcement.

Click to expand...

I said it was easy to do...and assumed the engineering would be done by the stabilizer people.

While I'm good at a lot of things...I know when it's time to rely on specific advice. Plus even a 2 foot square thickening pad may not be enough..it may have to be tied into the boats structural web,

But the glasswork itself is not rocket science UNLESS the engineer/architect calls for very specific, high tolerances on the strength of the epoxy and glasswork.

Guys, all this talk about naval engineers, is just really not how a boatyard does a retrofit, especially on an out of production boat.

If I take my boat to good recreatonal boat shipyard, what they are going to do is to beef up the area around the fins, and tie that beefed up area onto the nearest stringer.

Thats the reality of boat work. They are not going to hire a structural engineer to spend thousand of dollars on an engineering study.

While enlisting a naval engineer is the "proper" method, (I cannot argue that), it is just not how the job would get done.

The fiberglass guy will read the manual, look at the boat, and add the reinforcing pad to the inside of the hull.

Sitting at a desk behind a computer we often come up with theory on how a job should get done. When we step out from behind our screens, into the bilge we come back to reality, and get after the job.

In my boats case I have photos of where these things have went in the past. Its a pretty easy place to work in. I'm not going to do the fiberglass myself. Yes, I could learn these skills, but I don't want to learn on something this important. I'm guessing that the fiberglass reinforcement can be done for 3-4k in labor if I get things out of the way for the fiberglass guy. Thats probably in the ballpark labor wise.

GonzoF1 said:

Why not compressed air? These guys have my attention and I am considering this for Skinny Dippin'. I think for you, a 4-fin system would work well. Easy install, small footprint, lower pressures, cleaner (no oil spills), and I would bet a damn-site cheaper.

Gyro Gale Stabilizers

Tom-

Click to expand...

Thanks for the link.

While I won't discount their product, I'm going to go with a larger "brand" name supplier. I have quote requests out to Naiad, Trac, and Wesmar right now.

I need to study the technical details of each system and make a decision. They all seem to make quality products.

Many times a puchase decision is based on how helpful the supplier is. Thats probably how this one will work out. If a supplier is not helpful or forthcoming with answers to my questions then it's difficult to do business with them. We'll see

photos of fin install

Here's a couple of photos of fin installations on a Bayliner 4788.

The location for folks familiar with this boat is the foward head and the bunk stateroom

I'm going to look at the boat some more. The reason is that Naiad recommends the middle 1/3 of the WLL as OK, with center as best.

The location for this install is fairly far foward in my opinion, pressing the forward range of the install area.

Optimum would be aft a few feet. I'm thinking the mid stateroom would be better, but I'm going to look this weekend at whats in the way.

Just a question.

What does Bayliner say?

I have often heard that a bayliner is the most engineered boat on the water.

SD

psneeld said:

I said it was easy to do...and assumed the engineering would be done by the stabilizer people.

While I'm good at a lot of things...I know when it's time to rely on specific advice. Plus even a 2 foot square thickening pad may not be enough..it may have to be tied into the boats structural web,

But the glasswork itself is not rocket science UNLESS the engineer/architect calls for very specific, high tolerances on the strength of the epoxy and glasswork.

Click to expand...

You misinterpreted...usually the stabilizer manufacturers already have an idea of what to do or have inhouse guys to do the basics...see...it's right in the first sentence...

I know what you mean... I was a salesman for Wesmar stabilizers awhile back when I worked in marine electronics.

Fin manufacturers don't get specific on how to reinforce the hull for the actuators as they have no interest in paying for a sunk vessel where there is a question about whether more explicit standards were adequate for the particular bit of nautical stupidity that resulted in the sinking in the first place. In ABT's case, they have this disclaimer in big black letters on the installation manual:

It is the responsibility of the installer to determine what reinforcement
measures should be taken to properly strengthen the hull to withstand
forces that may be encountered in the event that the fin, and thus the fin
shaft, strike an immovable object while the vessel is under way.
Recommendations made by American Bow Thruster are to be used as
starting guidelines only. American Bow Thruster is NOT a naval
architecture firm and is NOT qualified to advise on structural matters.
American Bow Thruster strongly recommends that you seek the advice
of a naval architect familiar with your make of vessel.

I took their advice and I think I paid about $300.00 for a naval architect to provide the specs for reinforcement. With a steel boat, it is pretty easy to do the job in a way that its unlikely to sink the boat on a grounding. ABT's fins are also 'tear away' with the internal shaft designed to break off at an identified sheer force, so the reinforcement is supposed to exceed that by the margin calculated by a naval architect. I would definitely not trust a boatyard to 'wet finger' that calculation, especially with a fiberglass boat, which is probably what happened with the GB66 Marin mentioned, with the near result of a lost vessel.

If you send me a PM, I can send you the installation manual for ABT fins, which is full of useful information for someone contemplating adding active stabilizers.

One more question I would have - you indicated that Naiad indicated a pretty small fin area, which suggests to me they are recommending a system designed to operate at speeds of 10+ knots. Is that how you use the boat in conditions requiring stabilization?

Most venders have a recommended list for glass and installation. I would have a professional person do the fiber glassing. I mean why cut corners on the important areas. Also many installers don’t mind if you do some of the grunt work. I usually cut the holes, run the hose/wire, let them do the hook up and bless the system which is usually required for the warranty. Save about 25+% of the install.

I have talked to several fin representatives, and they did not recommend the fins for a slow, 6 to 10 knots, and/or they recommend large/huge fins, install ½ to 2/3 toward the stern. They all said for the money I would not be happy. A sister 58, Freedom, had active stabilizers which quit working, estimate cost make functional was 10+ grand, so he fiberglass the fins in place with a slight down angle which he says works about the same as when they were active/working.

But the glasswork itself is not rocket science UNLESS the engineer/architect calls for very specific, high tolerances on the strength of the epoxy and glasswork.


Naaahh they just specify it a bit thicker.

Weight is not a dirty word on a displacement boat so an extra 50 lbs of GRP doesn't harm a thing.

I thought I'd share this...

Last night i sent a request for information e-mail to Wesmar, and Trac via their web sites. I have already been in contact with Naiad, and am getting their quote through my favorite boatyard.

This morning at 08:30 pacific time I got a call from the wesmar rep. I liked that. They are right on the ball.

We discussed my installation and he told me that he would look up the installation records of their installs on a Bayliner 4788. He recommended a 6 sqft fin (same as Naiad recommended)

Within an hour I had a quote in my hands for the complete system, with options for the type of computer, which would be either a one axis (roll only) or a 3 axis (roll, pitch, yaw), fin options, instruction manuals, and even the cell phone number of someone that installed and tested their system on my exact model of boat.

I am frankly very impressed with Wesmars response and customer service. This is the way I want to be treated when spending this kind of dollars. i was also very impressed that once we talked about my background,they were quite happy to support me in an owner install scenario. They told me that is pretty common with their customers to do some or most of the work themselves and contract out parts that are not in the owners skill set.

I am also admittidly very impressed with Naiads response as well. Their rep has been in good contact with me, and has responded to every question, provided manuals, etc... Also great customer service.

I have eliminated the gyro from consideration. When I expressed my concerns about being the first boat on my size getting that particular model the response was to paraphrase "I wouldn't have been selling these for the last 6 years if they didn't work". Sorry, but thats not good enough.

So, unless Trac responds very positivly, I am happy to work with either Naiad or Wesmar. Since long term support is a very critical factor I'm going to do a D&B credit check on both companies to try to get an idea of their strength.

I found ABT to be pretty inept in sales process but peerless in engineering excellence and follow on support. just depends on which characteristics are most important to you.