Centerboard Keels in Blue Water Vessels

[deluxe68]

Originally Posted by denverd0n

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.

So, do you know anything about the Alden 44?

[autumnbreeze27]

Having owned fixed keel sailboats and currently owning a centerboard, here's the way I see it:

Advantages:
Under sail, you have the flexibility of trimming the keel for better performance or comfort
Shallower draft for going inshore
I've heard you can leave it partially down when coming to ground so if it hits you can crank it up and get off easier, but I'm not sure I'd try it.

Disadvantages:
Cost of maintenance
Ours used to bang at anchor if we had it down, but after we had it worked on (cutlass bearing replaced, and some damage fixed) it hasn't banged yet, but we've been working on it more than cruising it, so I'm not sure if that's fixed or if it will eventually come back.

[donradcliffe]

Originally Posted by denverd0n

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.

Yacht design is all about trade-offs, but it is a law of physics that the lower you put the ballast, the less tender the boat is. Therefore centerboard boats are more tender than externally ballasted keelboats. In spite of the simplistic stability calculators, the centerboard boats are going to be more likely to roll over in a storm.

[autumnbreeze27]

Originally Posted by donradcliffe

Yacht design is all about trade-offs, but it is a law of physics that the lower you put the ballast, the less tender the boat is. Therefore centerboard boats are more tender than externally ballasted keelboats. In spite of the simplistic stability calculators, the centerboard boats are going to be more likely to roll over in a storm.

True, yacht design is all about trade offs. For your comparison to work, you have to have a boat that is identical in every way except the centerboard, which is an unrealistic comparison. A properly designed centerboard boat might have a shorter rig, a lighter rig, more ballast, different hull shape, etc, to compensate, because everything is a trade off.

Consider the bene that sank this year on the way across the atlantic due to it's external ballast failing. If we lose our centerboard we'll lose stability and pointing ability, but we won't sink or turtle (stuck upside down)

When considering seas big enough to risk broaching, on a centerboard you can pull the board up, lessening the chance of the boat tripping on it. If you have a fixed keel, you don't have that option.

[maine50]

I have a Tartan 43 -"Northstar" (tartan 41 with traditional transom) that's a centerboarder. It was designed by Sparkman & Stephens as a change on the T41. (1974) It has approx. 1800lbs additional ballast for a total of 11000# on 24000# displacement. Board only weighs about 180#. The boat has done multiple trips to Bermuda and I trip to Caribbean and back. Most of the time we leave the board up. Finished Marion to Bermuda 1 hr later than fin keel sistership. Have no concerns about offshore. We have same rig as keel version. Only a few centerboards from the T41/43/44 series were made----Tim

[Curmudgeon]

My Bristol 38.8 is a centerboarder, as were all of them.

The boat will heel to 15 degrees pretty quickly. Then it stops. You have to be seriously overcanvassed to go beyond 20 degrees.

Having said that, it pays to reef early with my Bristol. In 17-22 knots of breeze it is jut as fast with a reef in the main as it is with no reef unless you are on a broad reach, and even then there's not much difference.

[Curmudgeon]

Originally Posted by deluxe68

So, do you know anything about the Alden 44?

I do know something about the Alden 44, because I know people who worked in the Tillotson Pearson yard when they were built and I've sailed on several, although I've never owned one. Beautiful boats. Not fast compared to a modern fin keeler but decent. Construction quality was good but not great (you won't be buying a Hinckley or Morris). The boats were semi-custom, so you can see some quirky variations from boat to boat.

The Mk1 version of the Alden 44 had crappy, small linear galleys located in the passageway back to the aft cabin. The later versions tend to have nicer galleys on the starboard side (IMHO port would have been better).

[Nicholson58]

Ours is a 1984 Camper Nicholson 58 ketch. 6'-8" board up with a long modified full keel. 13' board down. The upwind performance gain is about 4-5 degrees. I am not pleased with the complicated mechanics of ours. My opinion is that the design should permit easy replacement of the pennant by diving and a dedicated manual winch for lift & drop. I always worry I won't get it back up so we seldom use it.

[R-TRIumph]

I just learned of the Clearwater 35 and am very interested in purchasing one -have you been satisfied with the boat overall and particularly the board mechanism & sailing performance? Also, if you happen to know of any boats for sale I would be interested.

Thank you, Dennis

[sailorphil9]

For the record, Mirabella V (now M5). One design constraint was that she had to be able to use Palm Beach Marina.



https://en.wikipedia.org/wiki/Mirabella_V



Draught (keel up) 3.80 m (12.5 ft) (2013)
Draught (keel down): 10.20 m (33.5 ft) (2013)





https://vimeo.com/41840803

[Fore and Aft]

Here is another large swing keel Tall Ship that has logged some serious miles. I worked on her in 1996. The swing keel divided the accomodation.
Cheers
https://en.wikipedia.org/wiki/STV_Fair_Jeanne

[Steve Pope]

Originally Posted by R-TRIumph

I just learned of the Clearwater 35 and am very interested in purchasing one -have you been satisfied with the boat overall and particularly the board mechanism & sailing performance? Also, if you happen to know of any boats for sale I would be interested.

Thank you, Dennis

I havn't read the whole post, so forgive me for butting in, but I have a Trismus 37 that has 2 CB's one in the usual position giving 2m draught down and 1m with it up. The aft board is under the cockpit and adds 3/4 of a metre with it down.
This yacht has been to the Arctic, has rounded cape Horn, lived in Alaska for several years and now sails New Zealand waters. The boards are both unballasted alluminium. The main board is on its own winch and the aft one is on a light rope tackle. A very versatile boat, it wont point like a day racer but it will go to windward, ever so slightly eased sheets are better than pulled hard in. There have been around 400 Trismus 37's built, most in composite materials, and maybe 40 to 50 in Alluminium, whatever you go for the pluses for CB's are greater than the minuses.

[malbert73]

Love the CB on my very bluewater capable Tartan 40. Under 5 foot draft up, over 8.5 feet down. Yes ballast that deep would be better if shallow draft were not important.

[dfelsent]

Wow. Zombie thread comes back to life! [emoji1]
Moonbeam is 5.75’ centerboard up and 10’+ board down. Board is about 600 pounds of bronze out of 38000 loaded pounds of boat.
Board down makes upwind better, tracking on a reach better.
I had the pivot pin replaced out of caution last year. After 48 years and many miles the 1 1/4” pin had 1/8” of wear.
Yes the pennant is maintenance but the shallower draft is great.

Oh yeah and she was built for bluewater.

[R-TRIumph]

I may not be doing this correctly -new to the forum & threads, but hopefully you will see this. I appreciate the comment - I had never heard of the Trismus, but will add it to my list of prospective shallow draft boats.
Regards, Dennis

Originally Posted by Steve Pope

I havn't read the whole post, so forgive me for butting in, but I have a Trismus 37 that has 2 CB's one in the usual position giving 2m draught down and 1m with it up. The aft board is under the cockpit and adds 3/4 of a metre with it down.
This yacht has been to the Arctic, has rounded cape Horn, lived in Alaska for several years and now sails New Zealand waters. The boards are both unballasted alluminium. The main board is on its own winch and the aft one is on a light rope tackle. A very versatile boat, it wont point like a day racer but it will go to windward, ever so slightly eased sheets are better than pulled hard in. There have been around 400 Trismus 37's built, most in composite materials, and maybe 40 to 50 in Alluminium, whatever you go for the pluses for CB's are greater than the minuses.