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Picnic Sailor
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One of the boats I am currently considering is a Moody 42 - but with the shoal draft variant (4.92') of their keel as per below.



And here below if the standard deep fin version of the Moody 42 at 6.07'



Now I have an a basic understanding of keel types and their general characteristics and understand that offshore the deep fin is preferable but I guess I am wondering how much worse the shoal variant would actually perform offshore? How could I expect a keel such as this to behave?

To be clear my cruising plans include an Atlantic and eventually a Pacific crossing, but no plans to beat around capes in the southern ocean.

I have indeed previously asked about an older different shoal draft Moodys on here before so apologies for continuing to ask about this. I am struggling with how the different shoal keels perform, wing vs bulb vs scheel and I also understand there are degrees of shoal keel. To my understand this is not an 'extreme' shoal draft keel perhaps?

I was never great at physics at school!
 

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The obvious advantage to shoal or shallow draft vessels is the ability to anchor in or navigate through "thin" water.

Leeway is also an issue to consider... the keel will play a roll in both providing lift and limiting leeway... and be a factor in righting.

I am not a naval architect... Bob Perry is the one to address this... but I suspect that a well found shoal draft would be fine off shore and an asset for the regions of thin water.

Of course we sail only in favorable conditions.... but when you are on a long term cruise of months and years... you should be able to pick a the best weather window... or plan your voyage... considering prevailing winds and sea conditions.
 

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From the pictures you have posted, the shoal kell has some weight at the tip which indicates a correction for righting. But leeway is also important, the lateral area of the keel is responsible for this. Althoug fin keels are generally acceptable for ocean cruising most prefer long keels for stabilty. Is the stability of a shoal keel equal to that of deep keel?
 

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I actually tried to buy the boat in your first picture but was outbid. Incidentally it had been on the hard with blocked cockpit drains and there was significant water damage.

That is a Scheel keel (details of which you can find via google) which, according to the research I did at the time, sails very well. Unfortunately I never got to the point of actually sailing it. BTW, Moody used high tensile steel keel bolts which have to be sealed to prevent corrosion and warrant a close inspection on any boat you are looking at.

I found Moody Owners Association ( moodyowners.org ) friendly and helpful.
 

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There are several issues with shoal draft keels, the extent to which these are a deal beaker greatly depends on the specific boat and the specific owner. Starting with the specific owner, almost no matter how well or how poorly a particular boat performs, there will be an owner out there whose tastes and sailing style is such that they will be satisfied with the performance of that boat. So in other words, while any shoal draft keel will have limitations on some mix of performance, safety, and motion comfort, the degree to which a shoal draft keel is a deal breaker will be solely up to you.

But addressing the specifics of the boat in question, I will start by saying that in terms of sailing ability and motion comfort, the 6'-1" draft of the so-called deep draft keel, is already a shallow keel draft for a 42 footer. Its not extremely so, but if you are a person for whom performance is important, then even the so-called deep keel would be a deal killer. This is exacerbated by the hull form of this boat which has very deep canoe body and rounded transverse sections that supply almost no form stability. This results in a boat that is likely to produce a boat that inherently rolls through very large roll angles.

With that in mind the keel plays a critical roll in damping the roll, thereby reducing roll angle and roll accelerations. The effectiveness of a keel in damping roll is a product of its area and its vertical span. A keel with a longer span is much more effective in damping roll. On a boat like the Moody in question, the deep canoe body shortens the span of the keel significantly.

Adding more area to the can help with damping, but because of the way that damping works, it would require a significantly greater area on the keel and that greater area comes at the price of a lot more drag.

Similarly, this boat starts out with a hull form that does not help with stability. Therefore, as compared to a more moderate hull form, a proportionately large amount of this boat's stability comes from the keel. When you make a keel shallower it typically takes a lot more ballast to make up for even a small loss of the lever arm of a deeper keel. That would be the case in spades here. That can be mitigated partially by a bulb of some kind which Moody has done on both their so-called deep keel and on the shallower keel. But that bulb and that greater weight comes at the price of greater drag and lesser performance.

Lastly, as a keel gets shorter in span, it is less efficient for a variety of reasons such as a larger percent of the keel operating in the turbulent water near the hull, greater tip losses and vortexes, shorter leading edge, and so on. To partially offset those losses inefficiency the keel needs to have some mix of a greater area, and perhaps a end plate of some kind (i.e. Sheel Keel, Wing Keel, or a properly shaped bulb). Both of the Moody keels have some kind of a bulb shaped to form an end plate. The shortcoming of this is that the larger keel area, and bulb/end plate have much greater greater drag that hurts light air performance, motoring speed and fuel economy, and can greatly increase drag when heeled due to dynamically induced turbulence along the bottom of surface of the end plate due to leeway.

In the end, the shoal draft keel will roll more easily, faster, and through a wider angle, and will have some mix of poorer light air performance, will heel more in a breeze, make greater leeway, not make as good VMG to windward, and will burn more fuel when motoring. This of course may be offset by the flip side that you can get into shallower water and that might be worth the price to some people for having a shallower keel.

I also want to comment on this:
Although fin keels are generally acceptable for ocean cruising most prefer long keels for stabilty.
That is a somewhat misleading statement. Long keels and full length keels are not inherently more stable. In fact, to overcome the greater drag of the keel area and tip vortex, a long or full keel boat typically ends up needing to carry a proportionately greater sail area. This in turn means that they need much greater stability in order to carry the required sail area which they rarely have. As a result of that lack of stability long and fill keel boats typically end up with some mix of carrying relatively smaller sail area than they need, less efficient sail plans, and/or heeling at larger heel angles for the same wind strength.

One final note, I have been spending a lot of time around a slightly earlier Moody, and I have been appalled by the dismal build quality of that boat. I don't know whether Moody upped their game or not in the 10 years between the boat that I have gotten to know and the time that this boat was built.

Jeff
 

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Chall - I specifically chose a shoal keel Hunter (5' draft). I did so because the Gulf and Carib cruising grounds have a lot of shallows. And I'm very glad I did it.



Having done a good bit of offshore racing, I definitely wanted performance in a boat. BUT, I also think that the differences between these keel-types are so negligible in the big picture that it makes MUCH more sense to have a boat that keeps you off the bricks when around the bricks - than one that might give you another half-knot offshore...which will ONLY be in specific sailing conditions...if you're continually working the boat. And it will be relatively short-lived over the duration of your passage anyway.

For cruising boats, I'm a big advocate of the shoal keel. It's just a better all-round solution I think if your going long-range. Our 5' draft opened up MANY more opportunities for us than a deeper draft would (marinas, boat yards, channels, etc.). Yet, our Hunter did very well offshore. Great speed, great stability, great tracking. No complaints.

PS - I'm speaking only about the keel. I know nothing about Moody's specifically. So if, as Jeff says, they are prone to a lot of rolling, maybe it's not the keel that's the issue.
 

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I don't think that there is any secret that, on any given boat, a deep draft version sails better than a shoal draft version but, for many of us, the practicality is more important than the loss of performance. I was nervous of getting a shoal draft boat but a deep draft just wasn't practical for my intended use and, as it turns out, the wing keel Catalina 42 sails much better than I expected. Yes, it can get a bit rolly if you are getting hit on the beam but I've sailed much worse.
One final note, I have been spending a lot of time around a slightly earlier Moody, and I have been appalled by the dismal build quality of that boat. I don't know whether Moody upped their game or not in the 10 years between the boat that I have gotten to know and the time that this boat was built.
Jeff, I was interested in this comment. The build quality on boat I tried to buy seemed ok - not stellar but decent. And I was told that build quality tapered off towards the end in an attempt to compete on price with the French and German boats. Would you share with us which model this is and what you found?
 

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I actually tried to buy the boat in your first picture but was outbid. Incidentally it had been on the hard with blocked cockpit drains and there was significant water damage.

That is a Scheel keel (details of which you can find via google) which, according to the research I did at the time, sails very well. Unfortunately I never got to the point of actually sailing it. BTW, Moody used high tensile steel keel bolts which have to be sealed to prevent corrosion and warrant a close inspection on any boat you are looking at.

I found Moody Owners Association ( moodyowners.org ) friendly and helpful.
I apologize for picking nits, but that is not a Scheel keel. I own one. That thing has some kind of flat wings. A Scheel is more like a squashed elephant's foot or a modified bulb.

https://tartansailing.weebly.com/uploads/6/7/3/9/6739287/3339096_orig.png

http://photos.mostsailboats.org/1994/p/1994-Pacific-Seacraft-Cutter_14929_6.jpg
 

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Jeff, I was interested in this comment. The build quality on boat I tried to buy seemed ok - not stellar but decent. And I was told that build quality tapered off towards the end in an attempt to compete on price with the French and German boats. Would you share with us which model this is and what you found?
The boat that I have been getting intimately familiar with is a mid-1980's era Moody 34. You can see that boat in Youtube Series "Sailing Nevous'. I have been amazed at the poor glasswork, and less than stellar engineering on this boat. Regarding the glass work there is a huge amount of non-directional cloth, tabbing is incomplete and lightly done (even on the major structural bulkheads). The Youtube series shows many of the issues that they have discovered and are working to repair. I show up in a few episodes. The deck gear and rigging is a mix of some nice details and some really cheesy, bottom of the barrel kind of details.

While the interior was a nice layout and looked nicely done, the details were not all that well executed once you saw the backs of the cabinetry.

I will also note that back in the 1980's when my boat was in a marina, there was a Primrose era Moody in the next slip to mine that an acquaintance was restoring. That boat was shockingly crudely built as well. I had heard that Moody's quality had greatly improved over the years, and there is no doubt that the 1980's era 'Sailing Nervous' Moody is a much nicer built boat than the earlier Moody. I will also note that I have been on two larger and more modern Moodys and they seemed to be lovely boats but I did not study those for construction details like I was able to with the earlier boats.

Jeff
 

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Picnic Sailor
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Discussion Starter #12
One final note, I have been spending a lot of time around a slightly earlier Moody, and I have been appalled by the dismal build quality of that boat. I don't know whether Moody upped their game or not in the 10 years between the boat that I have gotten to know and the time that this boat was built.

Jeff
I would suggest on the more modern Moodys build quality was quite reasonable from the boats we have seen but by no means on par with the high end builders like say a Hallberg Rassy.

I note John Neal on his website describes their build quality as 'similar to Catalina'.

Thanks for the great write up Jeff. Appreciated and food for thought.
 

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I apologize for picking nits, but that is not a Scheel keel. I own one. That thing has some kind of flat wings. A Scheel is more like a squashed elephant's foot or a modified bulb.
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Hey, doesn't matter to me - a Scheel is only a slightly modified bulb anyway. But Moody and presumably Bill Dixon described it as a Scheel keel. If you look at it from directly in front, it does look very similar to your "elephant foot" diagrams; the pictures just don't show it very well. The Moody version does have small winglets added. I don't have a picture from the front but here is one from when I looked at it that shows the shape a little better.
 

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The boat that I have been getting intimately familiar with is a mid-1980's era Moody 34. You can see that boat in Youtube Series "Sailing Nevous'. I have been amazed at the poor glasswork, and less than stellar engineering on this boat. Regarding the glass work there is a huge amount of non-directional cloth, tabbing is incomplete and lightly done (even on the major structural bulkheads). The Youtube series shows many of the issues that they have discovered and are working to repair. I show up in a few episodes. The deck gear and rigging is a mix of some nice details and some really cheesy, bottom of the barrel kind of details.

While the interior was a nice layout and looked nicely done, the details were not all that well executed once you saw the backs of the cabinetry.

I will also note that back in the 1980's when my boat was in a marina, there was a Primrose era Moody in the next slip to mine that an acquaintance was restoring. That boat was shockingly crudely built as well. I had heard that Moody's quality had greatly improved over the years, and there is no doubt that the 1980's era 'Sailing Nervous' Moody is a much nicer built boat than the earlier Moody. I will also note that I have been on two larger and more modern Moodys and they seemed to be lovely boats but I did not study those for construction details like I was able to with the earlier boats.

Jeff
Thanks for that, Jeff. Very interesting.
The bigger Moodys, particularly the 54, have a descent reputation for quality, at least in the U.K. I wonder if they cut corners on the smaller boats.
 

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Picnic Sailor
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Discussion Starter #16
I actually tried to buy the boat in your first picture but was outbid. Incidentally it had been on the hard with blocked cockpit drains and there was significant water damage.

That is a Scheel keel (details of which you can find via google) which, according to the research I did at the time, sails very well. Unfortunately I never got to the point of actually sailing it. BTW, Moody used high tensile steel keel bolts which have to be sealed to prevent corrosion and warrant a close inspection on any boat you are looking at.

I found Moody Owners Association ( moodyowners.org ) friendly and helpful.
Thanks Geoff.

This is not the actual Moody 42 I'm looking at, but just the most convenient picture of the shoal keel variant I could find! Sorry to hear that this particular boat did not work out for you in the end.

The feedback I have had is also that they sail quite well (given that they are clearly not mean't to be a light air flyer) which is possibly at odds with some of Jeff's analysis but as he also suggests physics aside an owner can simply be satisfied with performance of their individual boat for their individual needs.

Thankyou also for the heads up on the keel bolts.

In the end, the shoal draft keel will roll more easily, faster, and through a wider angle, and will have some mix of poorer light air performance, will heel more in a breeze, make greater leeway, not make as good VMG to windward, and will burn more fuel when motoring. This of course may be offset by the flip side that you can get into shallower water and that might be worth the price to some people for having a shallower keel.
I am not surprised by your analysis I guess the question for me is to what degree, which is a hard thing to quantify and clearly yes only I can answer specifically to our individual needs and preferences.
 

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