# Wing vs Fin Keel



## TSOJOURNER (Dec 16, 1999)

I''d like to get some experienced comments of wing vs fin keels. I like the idea of a shallow draft but if I bottom out with a wing will it break off or dig in? If my slip drys out from under the boat will I damage the wing and its performance?

What do you think?


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## TSOJOURNER (Dec 16, 1999)

I think that evaluating a keel based on its ability to cope with a major screw up like leaving a keelboat in a slip that has no water at low tide is the wrong way to go about it.

If you really want a keel that holds up when the water is gone there are double keel boats built for just that purpose.

As to what happens to a wing or a fin when you ground (for what ever reason) there are a lot of variables. What speed are you planning to hit the ground at? will the ground be mud, rock or sand?

What is the keel made of? How heavy is the boat?

I''m not trying to bust your chops, I am trying to make the point that its not a simple question.


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## TSOJOURNER (Dec 16, 1999)

Also if you like shallow draft look at centerboards or leeboards.


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## eds928gt (Sep 28, 2001)

The Chesapeake has lots of crab traps to avoid. With a fin keel, I''ve yet to snag a trap. I hear folks with wing keeled boats snag them quite often.

Also, if I go aground, I can usually get myself extracated by backing down. If a winged keel boat goes aground the keel can act like a plow-anchor. Getting extracated is more challenging on a winged keel boat.
:^(

~ Happy sails to you ~ _/) ~


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## TSOJOURNER (Dec 16, 1999)

I agree with Tom3 on this one.It''s what kind of sailing are you wanting to do, not what kind of grounding do you expect. 
Another consideration is the wing keel is much more prone to wrapping the anchor rode in a tide verses wind anchorage. An aquaintance of mine has wrapped his wing keel 3 times in the last year.


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## SailorMitch (Nov 18, 2005)

I owned a Pearson 27 (draft 3''4") with a winged keel for 15 years, and last fall bought a Pearson 33 (draft 4''2") with a winged keel. Obviously I like the wing or I wouldn''t have bought the 33. 

My experience has been that with the shoal draft, you''re a lot less likely to run aground to begin with. But if you do, yes, you have a lot more surface area contacting the bottom than with a fin. Best way to get off is to power off with the boat as flat as possible. Heel it any and the wing digs deeper.

I''ve only touched bottom twice and both times the keel bounced off the bottom (mud both times) and the boat kept going. I probably was lucky, but the keel didn''t dig in. I think a fin would have in those two cases.

As for crab pots here on the Chesapeake, have never grabbed one with the wing. I had the anchor rode wrap around the keel exactly once in all those years -- and all I had to do was let out more rode. It dropped off the keel and the problem fixed itself.

As for the bottom of the wing being shaped like a plow anchor -- no way for the Pearson wing design. The bottom of the Pearson keel is shaped more like a Bruce anchor. 

In other words, pay attention to your depth meter because you don''t want to go hard aground, and you''ll be fine.

Email me directly if you have more questions.


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## TSOJOURNER (Dec 16, 1999)

Thanks for the insights. Of course I don''t plan to ground...didn''t plan on it when I bounced off last year either


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## Jeff_H (Feb 26, 2000)

This is partially exerpted from an article written for another purpose. By the classic definition of a fin keel, any keel whose bottom is less than 50% of the length of the boat is a fin keel. Fin keels came into being in an effort to reduce drag. Cut away the forefoot or rake the stem, as well as, move the rudderpost forward and rake it sharply and pretty soon you have a fin keel. Today we assume that fin keels mean a separated rudder (skeg hung or spade) but in fact early fin keels had the rudder attached in a worst of all worlds situation. They offer all of the disadvantages of both full and fin keels, but with none of the virtues. Unknowing or unscrupulous brokers will often refer to boats with fin (or near fin) keels as full keel if they have an attached rudder. 

Fin keels with separate rudders seem to be the most commonly produced keel form in the US these days. 

Fin keels have some advantages as well. They have less drag so they typically make less leeway and go faster. You can get the ballast down lower so in theory they are more stable for their weight. They are more maneuverable. They take better advantage of the high efficiency of modern sail plans and materials.

They have some disadvantages as well, many of these have been offset or worked around by modern technology but at some level they are still accurate critiques. They have less directional stability than long keel boats so the tend to wander more under sail. Since directional stability is also a product of the dynamic balance between the sail plan and underbody, in practice they may actually hold a course as well as a full keel. In general though you can expect to make more course adjustments with a fin keel. It is sometimes argued that the lower helm loads requires less energy to make these corrections so a fin keel may also require less energy to maintain course. This I think is a product of the individual boat and could lead to a debate harder to prove than the number of angels that can dance on the head of a pin. 

Fin keels are harder to engineer to withstand a hard grounding and when aground they are more likely to flop over on their bow or stern. (Although in 41 years of sailing, I have never heard of anyone actually experiencing this.) Fins typically have deeper draft. They are easier to pivot around and get off in a simple grounding. 

Shoal keel
A shoal keel is just a keel that is not as deep as a deep keel. Today the term seems to be applied mostly to shallow fin keels. Shallow full keels seem to be referred to as shoal draft boats. A shallow fin is a tough animal to classify. Like a fin keel with an attached rudder, I really think it has few of the advantages of either a deep fin or a full keel and has many of the worst traits of both full and fin. This can be partially offset by combining a shallow fin with a centerboard, which is a neat set up for shoal draft cruising.

Bulb Keel:
A lot can be done to improve a shallow fin. One way is to add a bulb. A bulb is a cast metal ballast attachment added to the bottom of the keel. They concentrate the ballast lower providing greater stability and sail carrying ability than a simple shallow keel. Traditionally bulbs were torpedo or teardrop shaped. They have been re-contoured to provide some hydrodynamic properties. Recalling the discussion on tip vortex from above. Shallow keels need to be longer horizontally than a deeper fin in order to get enough area to prevent leeway. This means that a shallow longer fin would generate more tip vortex and more drag than a deeper keel. The bulb creates a surface to turn the water aft and prevent it from slipping over the tip of the keel thereby reducing tip vortex. This does not come free since a bulb increases frontal area and surface area. There is a very specialized type of bulb keel called a Scheel keel (named for Henry Scheels who was its inventor) that is carefully modeled to reduce drag and maximize lift when used in concert with a shoal draft keel.

Wing keels 
Wing keels are a specialized type of bulb keel. Instead of a torpedo shaped bulb there are small lead wings more or less perpendicular to the keel. These concentrate weight lower like a bulb and properly designed they also are very efficient in reducing tip vortex. There has been some discussion that wings increase the effective span of the keel when heeled over but this does not seem to be born out in tank testing of the short wings currently being used in production sail boats. Not all wings are created equal. They potentially offer a lot of advantages, but they are heavily dependent on the quality of the design and I really think that many wing designs are not really working to their potential and are no where near as effective as the advertising hype that surround them.

Then there is the whole grounding issue. In 2002, the Naval Academy did a study of keel types and grounding. They found pretty that the popular perception that wing keel are harder to free is accurate. In their study, wing keels were extremely harder to free. Stright fins were much easier to free, especially when heeled, and the easiest keel to free was the bulb keel. 

As others have mentioned, I would either do a shallow bulb, fin or else a centerboard boat where shoal draft is critical. 

Jeff


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## TSOJOURNER (Dec 16, 1999)

Great detail and info for me... THANKS for the help! Phil


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## TSOJOURNER (Dec 16, 1999)

Does anyone know where to go to get a fin keel switched out for a wing keel. I know.... but it is going to a inland lake.


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## SailorMitch (Nov 18, 2005)

Check out www.marsmetal.com


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