[Rhodes22-list] Broken diamondboard centerboard

[ROGER PIHLAJA]

Hi Dave,

I forgot to answer your other question regarding sailing W/O the diamond board.

There are 2 aspects to this question.  You touched on the 1st issue re ballast weight.  You will find the boat is a little more tender.  You will have to shorten sail sooner.  But, most of the ballast is carried as lead encapsulated in the shoal draft keel.  So, the loss of the diamond board will not be that big of a deal.

The other aspect is the loss of hydrodynamic lift from no diamond board.  The shoal draft keel provides some lift all by itself.  But, this keel shape is not very efficient.  The diamond board makes the keel much more efficient.  You will find the boat will not point as high when sailing to windward.  This will probably be the most noticeable effect of no diamond board.  You will not be able to balance your helm by slightly raising or lowering the diamond board to shift the position of the center of lateral resistance.  But, this is a small effect.

Roger Pihlaja
S/V Dynamic Equilibrium
1978  Sanford, MI
Sent from my iPhone

On Jul 27, 2026, at 8:40 AM, ROGER PIHLAJA <roger_pihlaja at msn.com> wrote:


Hi Dave,

It's a little hard to be certain from your attached photo.  But, in my opinion, your diamond board failed by a sudden brittle then gradual fatigue failure mode.  Based on where I see the fracture failure, I would say your boat backed up into something with the diamond board down.  The impact caused the initial fracture and then short cycle fatigue in normal use completed the job.  All kickup centerboard boats are vulnerable to this kind to collision.  But, you are the 1st Rhodes 22 owner I am aware of to experience it.

You should have the centerboard well inspected because there may be damage there as well.  Is there any leakage from the centerboard well or pivot bolts into your bilge?

There is a lot in the archives re centerboard cap removal/replacement.  I doubt you will find anything re your type of centerboard failure.  I hope you will contribute an article to our archives once you get your diamond board fixed.

FYI, the kickup rudder is subject to the same kind of damage while backing up.  You might want to give your rudder blade, rudder head, the gudgeons & pintles, and the transom a close inspection.

Does your diamond board retract all the way into the centerboard well?  If not, then the centerboard rollers on your boat trailer may be at least a partial culprit.  The weight of the boat pressing on the diamond board via the rollers may have contributed.

Roger Pihlaja
S/V Dynamic Equilibrium
1978  Sanford, MI

________________________________
From: Rhodes22-list <rhodes22-list-bounces at rhodes22.org> on behalf of DAVID BERG via Rhodes22-list <rhodes22-list at rhodes22.org>
Sent: Sunday, July 26, 2026 1:17 PM
To: rhodes22-list at rhodes22.org <rhodes22-list at rhodes22.org>
Subject: [Rhodes22-list] Broken diamondboard centerboard

I experienced a failure of the diamondboard centerboard at the pivot. While leaving the dock in a modest amount of wind, I immediately noticed the boat was not sailing correctly. At all. It turns out the centerboard was dangling below the boat from the pendant. I realized this when I picked up some speed and the board started clonking on the bottom of the hull.  I got back to the dock, and with the help of some good friends, we managed to retrieve it by splicing on a thin but strong extension on the pendant and then retrieving the pendant by swimming under the boat and grabbing the line. Then used the winch to haul it up to the side of the boat.

Photo of board attached. It is clear to me that this damage happened a while ago as I can tell where the freshly broken part is. I have never grounded or had any other unusual stress on the board, but it was likely existing when I bought the boat.

I've searched the archive and haven't found anything about this kind of failure. A couple of questions: I'm thinking of leaving the repair (re-installation of board) to the end of the season. I have sailed enough with the board up to know that works well enough. I'm wondering how much I'll miss that extra weight carried low in the boat. (I'm going to give it a try this afternoon).

Has anyone else experienced this failure? If so, do you have any thoughts or insights on the repair process, especially with removing and reinstalling the CB cap after the repair? I'll take it to a reputable local boat yard, but it is always good to arrive knowing what I expect needs to be done.

Thanks,
Dave
Blue Loon
Minneapolis, MN
1996/2003

[ Sent From rhodes22.net ]

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