Centerboard Keels in Blue Water Vessels

[Stillraining]

I Think the key operative is to never get turned sideways running before the wind..but we all know it can and dose happen...and is unavoidable with a cross train rogue at night or while your below deck even during the day so not always avoidable.

For my boat I still like the Idea when it gets pretty ugly and especially when it gets to huge seas to have the board up in all but say clawing off a lee shore scenario...where the other possibal outcome is worse.

[Curmudgeon]

The Southerly brochures suggest that the optimal configuration in heavy weather is to have the swing keel in the half raised position.

[HHNTR111]

Our Cambria 46 is keel/centerboard. We draw 5'6" board up, 10'6" board down, and we go to weather great, when we want to. We also reach with comfort, and the long keel means we can heave-to when we need to. Board up, we can go to some neat places.

Great boat, but we need to keep that pennant in good shape.

[gotago]

I never liked the idea of a retractable keel, I always felt the keel was needed for stability.... In till the day i ran into kadey krogen 38, now that is my dream boat.

I would like to be able to go into shallower water than i am now, and i don't want to go to a cat or tri

Would a retractable keel mono hull be more stable than a cat or tri in heavy weather??

[HHNTR111]

To each their own, but in my view, a multi hull will pound badly in heavy air, if you need to do ANY windward work.

[sailorboy1]

I've become interested in a boat (to remain nameless so we don't discuss it instead) with a centerboard design and remembered this thread. Read it all and note that not a lot of repliers have a centerboard boat, but do of course have an option.

The boat I'm looking at has a draft of 4'4" up and 9' down. In some research is seems the board weights around 800 lb and from an orginal designer drawing it is filled with chopped strand/resin. Boat has DLR of 299 and a ballast/displacement ratio of 39%. The comfort number comes out to 34, but I think this misleading because the ballast is higher up. The SA/displacement is 14.7 and I'm sure this is a concession to carrying the ballast higher.

So back to the the question of SAILING; is this boat to perform reasonaly well you think? Except for a little less pointing ability and being able to carry more sail maybe a little whilevlonger when the wind picks up, is there really going to be a SAILING negative? I accept that there will be a speed reduction in the 8-12 knot sailing, but we are talking cruiser anyway.

So maybe we can bring the topic back to life and talk more about the sailing of such a boat (leaving the mechanical issues for another thread).

[davisr]

Glad you brought this thread back Don. I'd never noticed it before. Sorry that I can't comment on your question, but I also am curious about the point you raise about sailing ability. Specifically, I'm curious about smaller centerboard boats. For example, I've been wondering if there is anyone out there who has any experience with Hake Seawards. It seems like every issue of Sail magazine has a big two page ad for the Seaward26RK and 32RK. The ads show families relaxing on a tropical beach, but also show bluewater snapshots with captions that read "Sailing the Gulfstream."

[Roy M]

Thanks to JMolan for bringing the Searunner trimaran centerboards into the discussion. I now have a 90+ pound centerboard, constructed of redwood, carbon fiber and polyuethane foam bound in fiberglass, Kevlar and epoxy resin, which, like JMolan's, floats. There is nothing like being able to adjust the board down to go to weather, raise it to pass a shallow stretch or scoot over the kelp beds off Point Loma. Though not for the narrow use of match racing, it's hard to pass on the flexibility of cruising where you can change your draft from 3' to 7', as well as adjust the angle of attack and CLR. Plus, being able to pull it out with the halyard to make repairs if you have been overly zealous in pursuit of shallow water weatherly performance. Thank you Jack, for breaking the mono-multi barrier, again.

[HHNTR111]

When on the ocean, I've never gone hard on the wind for any length of time, except racing. So, the board helps when trying to lay a point or clawing off a lee shore.

The other thing is that you don't need to have the board down all the way. Sometimes, when power reaching, a little board virtually eliminates leeway.

Our keel is about 12 feet long. I don't have the stability numbers in my head, but she is comfortable in a sea, never broaches, I like the cutter rig, and the centerboard lets us do the ICW, for example, which a deep keel would keep us from doing.

So, for me, the conclusion is that a centerboard in a well designed boat gives a great deal of flexibility with not much downside.

[davisr]

For those who may be interested, the Oxford Companion to Ships and the Sea has an intriguing article on the centerboard, or "Centreboard," as they spell it. In the Western world, centerboard vessels were invented on the east coast of America during the colonial period. The British picked up on the idea and began constructing centerboard sailing vessels, one of which, a 60 ton brig, the Lady Nelson, was the first to sail around Tasmania. This voyage resulted in more centerboard vessels being built for shallow water exploration. The article also speaks of centerboard schooners from the U.S.A. that were up to 150 feet in length.

All in all, it seems that the blue-water capabilities of a centerboard vessel are primarily dependent upon the quality of the vessel itself, and, of course, the quality of the captain and crew.

[deluxe68]

Originally Posted by HHNTR111

When on the ocean, I've never gone hard on the wind for any length of time, except racing. So, the board helps when trying to lay a point or clawing off a lee shore.

The other thing is that you don't need to have the board down all the way. Sometimes, when power reaching, a little board virtually eliminates leeway.

Our keel is about 12 feet long. I don't have the stability numbers in my head, but she is comfortable in a sea, never broaches, I like the cutter rig, and the centerboard lets us do the ICW, for example, which a deep keel would keep us from doing.

So, for me, the conclusion is that a centerboard in a well designed boat gives a great deal of flexibility with not much downside.

I am eyeballing an Alden 44, a few weeks ago I read something about centerboards being tender. Is there any truth to that?

[Steve Pope]

Centreboarders tend to rely on form stability rather than a deep ballasted keel, in my experience they are often stiffer at anchor, don't roll so much for the same reason. Once you learn how to sail them, you will not notice a lot of difference, you tend to shorten sail earlier, which reduces the heeling moment. Rarely can you point like a leadmine 40+ degrees is pretty good, you don't pinch when on the wind, speed normally equals the extra distance sailed. Alden CBders have been around for ever, tried and true. With a CB your available cruising area is hugely increased.

[roverhi]

Originally Posted by deluxe68

I am eyeballing an Alden 44, a few weeks ago I read something about centerboards being tender. Is there any truth to that?

Depends a lot on the boat. The Bristol 39-40 was built as both a center board and deep keel boat. They just cut a couple of feet off the bottom of the keel, extended the fore/aft position of the ballast so they could get the same amount of lead in the keel. The C/B boats have a reputation for being more tender than the deep keel version because they both have the same hull form but the deeper keeled boat has a greater righting moment. A boat designed as a center boarder will have flatter bilges and more beam to give it greater form stability. Consequently they will have greater initial stiffness than a comparable boat designed with a deep keel. The above doesn't som much apply to the modern flat bottomed boats as you can't get a flatter bilge so increased beam is the only way to go. So the question you need to get answered is was the Alden 44 designed as a centerboard boat or just a deep keel design modified to have a centerboard.

[deluxe68]

Originally Posted by roverhi

Depends a lot on the boat. The Bristol 39-40 was built as both a center board and deep keel boat. They just cut a couple of feet off the bottom of the keel, extended the fore/aft position of the ballast so they could get the same amount of lead in the keel. The C/B boats have a reputation for being more tender than the deep keel version because they both have the same hull form but the deeper keeled boat has a greater righting moment. A boat designed as a center boarder will have flatter bilges and more beam to give it greater form stability. Consequently they will have greater initial stiffness than a comparable boat designed with a deep keel. The above doesn't som much apply to the modern flat bottomed boats as you can't get a flatter bilge so increased beam is the only way to go. So the question you need to get answered is was the Alden 44 designed as a centerboard boat or just a deep keel design modified to have a centerboard.

As far as I can tell there were no Alden 44's built without centerboards.

[denverd0n]

Originally Posted by deluxe68

I am eyeballing an Alden 44, a few weeks ago I read something about centerboards being tender. Is there any truth to that?

The short answer would be "no." Having, or not having, a centerboard does not make a boat tender. It is all about the hundreds of other decisions that a naval architect makes in the process of designing a boat. There are some centerboard boats that are tender, and there are some that are not. There are some fixed-keel boats that are tender, and there are some that are not. Any suggestion that all centerboard boats are tender, simply by virtue of having a centerboard, is utterly and absolutely wrong.