# Shoal draft for bluewater?



## chall03 (Oct 14, 2002)

So our boat search has seen us fall upon what looks to be a well priced, immaculate condition Moody 44 that ticks all our boxes with the one red herring being that it is the shoal draft variant (So a 4'11"/1.5 m wing keel).

Now my basic premise has always been deep keel for Bluewater sailing but....well..

I looked at the polars for this boat and considering that shoal draft does give us other advantages I am pausing to consider how big a 'compromise' it actually is when it's upwind performance while far from being acceptable for racing does not look atrocious. 

I should define our version of 'bluewater' is a going to be Med cruising, the ARC, Caribbean and then a South Pacific crossing. We are cruising. 

I have no intention of beating across the roaring forties. 

As I see it basically I am looking at more reduced windward performance and thereby more motoring. Secondly I should also expect more leeway particularly in a big sea. Is that it?

So talk me out of it? Have I gone insane?


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## roverhi (Dec 19, 2013)

The reduced windward performance will probably only be noticed if you are going 'one design' against a same build deep keel boat from the same manufacture. It could also be a problem if you run aground as a wing keel will be harder to pull off. Most boats are floated off by a rising tide, however. For your cruising area, you won't really need the benefit of shallow draft so a deep keel version would be a no lose choice. Boat will probably need to be reefed earlier though, once again, you may not notice the difference.

I've got a center board boat and I so seldom sail with the board down, it's almost a waste.


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## ianjoub (Aug 3, 2014)

I have wondered the same. The boats we are looking at have a standard 10' draft. The super shoal version is only 6' with centerboard up, 13' with it down.


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## capecodda (Oct 6, 2009)

I have a shoal draft boat now. The boat before was a center boarder. Where I live it's essential, or I cannot get even to my home dock. I have also owned full keel boats, and fin keel boats when I lived where draft didn't matter much.

IMHO nothing beats a lot of weight on the end of a thin blade when it comes to performance. That said, nothing beats a full keel when sailing off the wind and requiring a minimum of attention to steer. I've balanced a full keel boat, locked the wheel, and walked away from the wheel for an hour. The other advantage is the prop is in an aperture, and somewhat protected. In-between is skeg hung rudders, with longer keels. More robust in grounding, less performance than a blade and a spade, more directional stability...but not a bad compromise. 

I guess I wouldn't buy a shoal draft unless getting into shoal places was a priority. I might if I was crossing oceans value stability on a reach or run over upwind performance, and want something with a longer appendage, more weight, less aspect ratio in the air and in the water. I'd like cutters and solent rigs to go wing on wing downwind in the trades, but can be a PIA when short tacking into a bay. I might like a skeg hung rudder over a spade. 

Or you could go all deerfoot-like and count on going like **** to outrun everything. A reasonable idea IMHO.

Nothing is a mistake, what matters most in these tradeoffs is what matters to you. Lots of reasonably built boats will work. 

All boats are compromises IMHO.


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## Minnewaska (Feb 21, 2010)

Might be a terminology mismatch here. If I read the OP correctly, they are asking about shoal vs deep keel, not necessary a full keel (the length of the hull).

There is no denying that a deep keel will perform better, but I don't think that's a selling point for a cruising boat. No one chooses to cruise to weather for very long. Getting that last 5 or 10 degrees of pointing into the wind isn't worth limiting your anchorage choices, especially storm holes, IMO. That said, this is a close call, so I would not make it a requirement either way.


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## JimsCAL (May 23, 2007)

It's easy to generalize, but each design is different. My Cal 33-2 is the shoal keel version (4'8" vs 6'2"). Not a wing, a longer fixed keel with a shape obviously designed to get weight down low. I had a conversation with the previous owner about its upwind performance , stability, etc. and he said he was very happy with it. And I knew the boat had had a decent record in club racing. In most PHRF regions, the shoal version is rated 6 seconds per mile slower than the deep keel version. Here in western Long Island Sound, it's rated the same. I;m sure I have a bit more leeway going upwind than the deep keel version, but it is not noticeable when sailing, and the boat is not tender at all. And I do enjoy being able to sneak into places I would be concerned about with a deep keel.


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## chall03 (Oct 14, 2002)

Minnewaska said:


> Might be a terminology mismatch here. If I read the OP correctly, they are asking about shoal vs deep keel, not necessary a full keel (the length of the hull).


That is correct.

Obviously the general discussion is still interesting but specifically the boat I am looking at is a Moody 44 with a modern 'shoal draft' keel variant as opposed the standard deeper fin keel found on these boats.


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## Jeff_H (Feb 26, 2000)

I am always suspicious of the types polar diagrams being published these days. There are comparatively accurate polar plots which can be produced with very high tech programs, and then there are a bunch which only provide extremely rough approximations. It is normally these rough approximations that get published. 

And while the sophisticated programs do a nice job of modeling the impact of relative small tweaks to the hull and rig, even the really sophisticated programs do a pretty mediocre job of modeling the relative effectiveness of various keel variations. And it is also important to understand what is not reflected on these types of polars, such as sail change and reefing requirements, leeway and heel angle. 

What I will say is that no matter what the designer does, designing a 44 foot boat to this extremely shallow draft is bound to be a much bigger compromise through a broader range of conditions than you are suggesting that the polars indicate. 

More specifically this boat has a comparatively round bottom and deep canoe body. This means that it develops very little form stability. But also its vertical center of buoyancy will be quite low. To develop stability on a boat with a low vertical center of buoyancy and a high vertical center of ballast on a boat with small form stability, requires a lot of ballast carried as low as possible (hence the wings) and a larger heel angle before much stability is developed.

What that means in terms of sailing ability is a mix of a boat that will need to be reefed sooner and have more frequent sail changes if it carries enough sail to sail in lighter winds, and/or a boat which gets motored more frequently at the low end of the wind range. This is in part reflected in the dismal SA/D of this boat. To overcome that you are either carry really big headsails and make headsail changes for the conditions, or motor more frequently. 

But the shallow keel does a lot more than that. As we now know, a key component of roll moment comfort is damping. Damping and roll resistance are largely achieved by the resistance of swinging a deep keel through the water, by a large polar roll moment of inertia (ideally from weight well below the roll axis), and from moderate amounts of form stability that develop progressively with heel angle. The net result of a keel this shallow is that it lacks the lever arm between the roll axis and the roll resistance so it provides very little damping, and diminished moment of inertia. The net result of combining this shallow a keel with a round bottom design like this is that the boat would tend to roll through wider roll angles and would tend to snap at the end of rolls because of being out of sync with the wave train and because it would tend to suddenly build form stability as the comparatively flat area of the topsides becomes immersed. 

Then there is the leeway issue. Shallow keels tend to be way less efficient for a variety of reasons; they lack leading edge length, they are operating in the turbulent area adjacent to the canoe body, they require a lot more wetted surface to achieve the same lift and so on. Which all means some mix of more drag and/or more leeway. At small heel angles wings act as end plates and help some by reducing the impact of tip vortex and low to high pressure side leakage, but that comes at the price that they add more drag due to wetted surface. At higher heel angles wings do add some lift to windward, but again as designed in most yachts, that lift is minor compared to the added drag of the wings being dragged at a relatively large incident angle through the water. 

But lastly, wings keels have been found to be much harder to dislodge from a grounding. 

Which is why, very few designers use wing keels for any purpose anymore.

And this sounds like the use of a wing keel in the worst possible way. 

Respectfully,
Jeff


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## fallard (Nov 30, 2009)

Another option--but not on the OP's radar--is a swing keel boat, like the Southerlys. I have a 35' Clearwater that draws about 2' with the weighted keel and rudder retracted, and about 6' with the keel down. My boat is not tender: if I am heeling more than 15-20° I am overpowered and would not lose speed to reef. With inboard shrouds, this boat points with the best of them, so I also have the weather advantage.

If the larger Southerlys have similar characteristics, this might provide the benefits of serious shoal draft when needed and deep draft for upwind performance. It's just a matter of price. 

The one downside of a very shoal draft is that you can easily get yourself into trouble because the charts--electronic or paper--don't have accurate soundings in really shallow water. The upside in my case is that I can keep my boat at my home dock in 2.5' at MLW (which is deeper than the charts would indicate.)


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## fallard (Nov 30, 2009)

OBTW, one of the other 6 Clearwater 35's did a circumnavigation. 

My delivery trip was 1700 miles from Clearwater, FL (a coincidence) to Mystic, CT, including a 3 day offshore stint of 600miles and another overnight offshore of 150 miles. My first mate--a veteran offshore sailor--on the offshore legs of that trip recommended that I do the Bermuda one-two. Never did it, though.


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## chall03 (Oct 14, 2002)

Jeff_H said:


> I am always suspicious of the types polar diagrams being published these days. There are comparatively accurate polar plots which can be produced with very high tech programs, and then there are a bunch which only provide extremely rough approximations. It is normally these rough approximations that get published.
> 
> And while the sophisticated programs do a nice job of modeling the impact of relative small tweaks to the hull and rig, even the really sophisticated programs do a pretty mediocre job of modeling the relative effectiveness of various keel variations. And it is also important to understand what is not reflected on these types of polars, such as sail change and reefing requirements, leeway and heel angle.
> 
> ...


Jeff thank you again so much for sharing your expertise and informed opinion as you have done countless times over the years.

Your knowledge and the time you take to share it is one of the things that I love about Sailnet.

So I actually spent alot of last night thinking hard upon this boat and made the decision this morning that it is not the boat for us and the sailing we wish to do.

To wakeup and read your well articulated thoughts only further confirms my decision.

I was swayed briefly by an attractive purchase price and the great condition this boat is in.

Buying second hand boats is a game of priorities and compromises but alas I think this compromise is one I will not take on.


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## chall03 (Oct 14, 2002)

fallard said:


> Another option--but not on the OP's radar--is a swing keel boat, like the Southerlys. I have a 35' Clearwater that draws about 2' with the weighted keel and rudder retracted, and about 6' with the keel down. My boat is not tender: if I am heeling more than 15-20° I am overpowered and would not lose speed to reef. With inboard shrouds, this boat points with the best of them, so I also have the weather advantage.
> 
> If the larger Southerlys have similar characteristics, this might provide the benefits of serious shoal draft when needed and deep draft for upwind performance. It's just a matter of price.
> 
> The one downside of a very shoal draft is that you can easily get yourself into trouble because the charts--electronic or paper--don't have accurate soundings in really shallow water. The upside in my case is that I can keep my boat at my home dock in 2.5' at MLW (which is deeper than the charts would indicate.)


I really admire the Clearwater 35. You have a great boat.

I also admire the Southerlys, as you said though a matter of price.

The comparable Southerly 135 while a great boat is literally 2 1/2 x the asking price of the Moody 44 I referred to above.

2001 Northshore Southerly 135 Sail New and Used Boats for Sale -


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## Minnewaska (Feb 21, 2010)

Jeff's post was excellent, as always. However, the cruising grounds you've mentioned have been sailed on far less capable boats than a Moody 44. When you find your boat, with a deep keel, it will very likely not have something the M44 has. It's just the way it works. 

I would offer that the vast majority of the time you spend aboard on a cruise like you describe, will have nothing to do with how she handles in given seas or winds. Clearly, you must have a hull that is solid and capable to handle it, if not ideal form. 

The only minor exception I would take to Jeff's review is that virtually no cruiser will be changing head sails for any reason. They will have a furler. Not as efficient, but cruising is rarely about maximum efficiency. Many long range cruisers will even slow a boat down to reduce the odds of breakage. Also, grounded/buried wing keels are an issue and I would prefer a bulb over a wing, for a shoal keel. But, how frequently have you grounded? At 4' 11", its hard to imagine how you might get in that kind of trouble. We're talking water you could stand in.

It's all about compromises and I understand you're not interested in this one. Just some food for thought, when you find the next compromise.


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## chall03 (Oct 14, 2002)

Minnewaska said:


> Jeff's post was excellent, as always. However, the cruising grounds you've mentioned have been sailed on far less capable boats than a Moody 44. When you find your boat, with a deep keel, it will very likely not have something the M44 has. It's just the way it works.
> 
> I would offer that the vast majority of the time you spend aboard on a cruise like you describe, will have nothing to do with how she handles in given seas or winds. Clearly, you must have a hull that is solid and capable to handle it, if not ideal form.
> 
> ...


All good points.

I have no doubt a shoal draft Moody 44 could do what we want. I guess specifically I just do not personally require a shoal draft keel so seems silly to head down that path. Sure it would be handy in a couple of places yes.(Namely Tonga) but it is not a priority for us.

I do in general like the Moody 44 design along with the older 425 and the newer 42. We are currently focusing on standard keel variants of these boats.

As you say it is all about compromises. I feel when looking at 20 year old boats for long term cruising condition is also a major factor.


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## Minnewaska (Feb 21, 2010)

Yup, those are the choices only you can make. I suspect the deep keel on that boat is not all that limiting anyway. Although, the more opportunities to run up a river or hide in the mangroves from a big storm, the better. Good luck.


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## Jeff_H (Feb 26, 2000)

ChallO3,

Thank you for the very kind words. 

I want to comment on Minnewaska's points regarding my post. As usual Minne has made some very important points. Minne is 100% right that by and large, the vast majority of cruisers, especially on boats this large, never make headsail changes, relying instead on furling their genoas when the breeze builds. Because there is a limit in how much a genoa can be furled before it becomes so misshapen that it is providing way more heel than net drive, the general compromise is to use genoas in the 130-135% range and to furl them down to perhaps 110% or so before they become badly deformed. Given boats that have masthead rigs and SA/D's in around 15-16 or so, this pretty much eliminates reasonable sailing speeds in winds under about 8 or so knots. There are a lot of venues where that lower wind range is rarely if ever needed, but in many of the popular sailing areas of the world (such as the Med in from late spring to early fall), the loss of the lower end of the wind range makes for a lot more motoring. 

Minne's point is also exactly right about the wing keel grounding as well. Running aground is pretty rare. If you are sailing in a venue where deep keels are the norm, then grounding is especially much less of an issue. 

I must admit that in hindsight my comments were in large part influenced by the venues that I have sailed in, Long Island Sound, Barnegat Bay, the Florida and Georgia Coasts, Chesapeake Bay, Maine Coast, and the Bahamas. These are all areas where running aground can and does happen on a more frequent basis. So, while I have mostly avoided groundings while owning deeper draft boats than conventional wisdom might suggest in these venues, I have also observed that the bottom contours seem to change a lot in these shallower venues, and that people with shoal draft boats seem more willing to cut things closer than I might. 

I also strongly agree with the comments above that if shallower draft is desirable, bulb keels are a much more effective option than wings, and if going even shallower than can be accomplished with a bulb, then keel/centerboarder boats are also a great option. 

Jeff


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## fallard (Nov 30, 2009)

Minnewaska said:


> Yup, those are the choices only you can make. I suspect the deep keel on that boat is not all that limiting anyway. Although, the more opportunities to run up a river or hide in the mangroves from a big storm, the better. Good luck.


When I sail, my draft is 6' virtually 100% of the time and it matters to be able to go to weather. But when I come into a harbor, I find them larger, with more anchoring options if I pull up my "landing gear" until I am drawing 4' or less. That matters a lot in areas like Block Island, Cuttyhunk, Provincetown, and--particularly--Nantucket, where available mooring balls are scarce. It really mattered when I pulled into a harbor of refuge (Point Lookout) in the Chesapeake, expecting 6' or deeper water according to the boating facility there, but encountered 5'.

It also matters when slips are limited and only the shallow water ones are available. It also matters when shortcuts are available for shoal draft sailors. We've found shallow draft a game changer in CT, NY, ME, FL, VA, and MA over the years.

We're not talking Tonga here, but once you've experienced the freedom of shallow draft, it's hard to consider deeper draft unless there are no other options to meet your other needs.


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