Winged Keels

[herbhunt]

We own a Farr Pilothouse 50. These boats come with an option of either a substantial winged keel or a traditional keel. The winged keel is 6.5' draft the traditional is 8' draft. Farr says there is essentially no difference in performance. So from this data you can see the first benefit of the winged keel - shallower draft - which comes from the combination of the lower cog of the keel (heavy wing at bottom) and the increase effective draft when heeled. The major disadvantage of the winged keel is somewhat theoretical - harder to pull off if you run aground. For us, the only time re really notice a difference (and this is anecdotal) in sailing characteristics is when we are on a beam reach in larger/breaking waves. In these conditions the boat seems to 'stick' in the wave where other boats we were sailing with were having to change course to avoid sliding down the wave face. For us the major advantage is the shallower draft as we are often in waters where this makes a difference.

[Group9]

Originally Posted by rognvald

All these people running aground! What have we been doing wrong all of these years? Perhaps we are too conservative in our navigation, perhaps we purposely avoid a bull's rush into uncharted waters, or maybe we're just lucky. In the last 20K miles sailed on our winged keel from the Gulf of St. Lawrence to the lower Caribbean, we ran aground once . . . and it was my fault. .

I probably ran aground more my first year of sailing that every other time in all the other years put together.

We just managed to sail all the way from Mississippi, to the Bahamas, and back, in a five foot draft winged keel, and managed to only run aground once (trying to jump a spoil bank next to the ICW in Florida that I knew about, but didn't feel like waiting four more hours for high tide to clear).

[Flextron]

It was just a fad post Australia 2 victory in the Americas cup.

If they were any good they would be on modern boats.

So not something that has stood the test of time. Don't bother

[knot smart]

Our bene 35 had a wing keel. I'm not astrophysicist but the theory is you get the same performance out of a shorter winged keel that you would a longer fin keel. Therefore increasing the versatility of your boat allowing you to get into shallower water. Think about it, if you had a 5 ft long winged Keel that performed as good as a 7 ft long fin keel you'd have the best of both worlds. Whether the theory is correct? Well, that's above my paygrade. But i loved that boat. That boat was great . Besides it being a big heavy chunk of metal to lower the center of gravity, the constant downward pressure due to the shape of the wing it will keep the boat more stable. But then again, what the hell do I now? I just sat in the cockpit drinking beer

[CptCrunchie]

Originally Posted by knot smart

Our bene 35 had a wing keel. I'm not astrophysicist but the theory is you get the same performance out of a shorter winged keel that you would a longer fin keel. Therefore increasing the versatility of your boat allowing you to get into shallower water. Think about it, if you had a 5 ft long winged Keel that performed as good as a 7 ft long fin keel you'd have the best of both worlds. Whether the theory is correct? Well, that's above my paygrade. But i loved that boat. That boat was great . Besides it being a big heavy chunk of metal to lower the center of gravity, the constant downward pressure due to the shape of the wing it will keep the boat more stable. But then again, what the hell do I now? I just sat in the cockpit drinking beer

My thinking also. Thanks.

So many schools of thought about them. While I do understand a winged keel needs to be heavier to provide the same 'leverage' as a fin keel, as long as the hull can handle it, and I have no issue losing a little speed and angle to wind, I like the idea of being able to anchor a little close to shore, or in a slightly more secluded bay because other fin keels can't enter.

I understand I don't NEED a shoal keeled vessel the South Pacific, but I do like the idea someone posted that it would be slightly more stable on anchor, like Naiad stabilizers that don't pivot.

[chowdan]

I parked on the hard in Everett for a few months while working on my boat. She looks like the one that was just down from me. Always wondered how she sailed and how she looked on the inside.

[MartinR]

Originally Posted by CptCrunchie

While I do understand a winged keel needs to be heavier to provide the same 'leverage' as a fin keel

No, this is not so. It works more like a bulb keel and concentrates more of the weight in the lower part of the keel. For many boats, wing and non-wing keel are the same weight and have the same center of gravity, and there is very little difference in sailing. A small loss in pointing ability, maybe.

This said, designing a wing keel is not easy, and there are probably many boats out there with is a profound loss of sailing performance due to bad wing keel design.

For most modern boats, wings do not work well, as keels are higher aspect ratio.

[CptCrunchie]

All you experienced wing keel sailors, I have a question that only you can really answer.

We are still mulling over the wing keeled boat I referenced in the OP. So far, I am encouraged, and will likely put in an offer.

Yesterday, I spoke with an older sailor about wing keels, a guy who said he knows a lot about them, but admitted he has never sailed one. We got talking about heaving to in big seas.

I started out heaving to with the genoa and mainsail, but quickly discovered it is far more comfortable for me, and far less stressful for the boat to heave to on just the mainsail. I have since done this in all sea states, and much prefer it to using 2 sails and/or a drogue.

This old salt said that heaving to on a wing keeled boat will be a challenge, because as the wave rolls under the boat, the leading wing will catch the wave as the wave breaks. This will make it roll the boat and either bring the boat up through the wind, or force it to roll sideways into the trough.

While I know very little about the effects of a wing keel heaving to, I don't see how it would go through the wind because the angle of the rudder would never let that happen, and it can't roll into the trough because the sail would be powering up.

What say you?

[MartinR]

Originally Posted by CptCrunchie

All you experienced wing keel sailors, I have a question that only you can really answer.

We are still mulling over the wing keeled boat I referenced in the OP. So far, I am encouraged, and will likely put in an offer.

Yesterday, I spoke with an older sailor about wing keels, who admitted he knows about them but has never sailed one. We got talking about heaving to.

I started out heaving to with the genoa and mainsail, but discovered it is far more comfortable for me, and far less stressful for the boat to heave to on just the mainsail. I have since done this in all sea states and much prefer it to using 2 sails and/or even a drogue.

This old salt said that heaving to on a wing keeled boat will be a challenge, because as the wave rolls under the boat, the leading wing will catch the wave as wave breaks. This will make it roll the boat and either bring the boat up through the wind, or force it to roll into the trough.

While I know very little about the effects of a wing keel heaving to, I don't see how it would go through the wind because the angle of the rudder would never let that happen, and it can't roll into the trough because the sail would be powering up.

What say you?

This is a funny idea A winged keel behaves much like any other keel in this respect. If the wings would be much wider, like an airplane, he might be right. No worries.

[a64pilot]

I’m thinking that as heavy as a winged keel is that it’s going to take significant speed through the water to even come close to getting enough lift to reduce that great weight, when hove to the boats speed thru the water is pretty much nil.
Yes waves roll under you, but if they aren’t breaking waves, it’s just the energy that rolls under, very little water movement in a non breaking wave as I’m sure you know.

[knot smart]

Hmm.. I say the wing gives the boat a lower center of gravity ( even lower than a fin, but probably equal to a bulb keel) ..so by definition the boat would have a harder time trying to roll.. And if you are that far off shore and conditions are bad enough to roll the boat, you have other things to worry about.. And besides, it'll right itself upright anyway

[CptCrunchie]

Thanks for the comments.

From what I gathered, the old salt was talking about the shape of the huge wing. Since the boat would be sitting some 45 degrees off the wave, he believes the wing would somehow hook into the wave as it rolled under, ...where a fin keel wouldn't. Anyone understand what he may be referring to?

I agree with you people; the significance of a wave rolling under the boat would have minimal effect on that wing while hove to, .....but something in the back of my brain thinks there must be more to this.

[a64pilot]

As long as they have been being manufactured and they way people love to hate things they don’t have, if there was any real drawback to a winged keel then some groups would be decrying it from the heavens.
You know more of the Cats flip, Mono’s sink, certain anchors aren’t worth carrying etc.

About the only credible detriment of a winged keel that I have heard of is that if you get one stuck in the mud, it’s more difficult to get out, and more easily damaged.

[CptCrunchie]

Originally Posted by a64pilot

About the only credible detriment of a winged keel that I have heard of is that if you get one stuck in the mud, it’s more difficult to get out, and more easily damaged.

My thinking, exactly. Think I'll leave the old salt to his beliefs. He has a wooden boat, and I thought about asking him what he thought about fiberglass, .....but me-thinks I know already.

[Dave_S]

Take this with a grain of salt, I have now become an expert in fluid dynamics from about a week reading posts on the internet. :-)

At lower speeds, probably under 10 or more knots, drag will exceed lift. I doubt there is any angle of attack built into the design.

Pinching hard upwind you will be close to stalling sails and keels, the wings will assist in keeping flow attached to the keel, over it's length and it will sail like a longer keel except that you won't have as much resistance to change as the keel with a larger surface area further from it's pivot point. Also going upwind you are likely to have an increase in apparent wave period. The wings will significantly change the boats reaction in the swell.

As the boat moves from level to bow up, the drag below your pivot point increases resisting the bow rising and when you crest the wave you will come down earlier so not as high. As the boat transitions to bow down the drag will pull the bow down and it will bury the bow deeper.

I think the net result will be slower and wetter.