Daggerboards or Fixed Keels?

The decision to use fixed keels rather than daggerboards has to be consistent with the ocean voyaging intentions for the design.

Daggerboards are a complicated and vulnerable installation. The benefit of possibly a few more degrees of pointing ability has to be weighed against several disadvantages such as; the difficulties of blocking the vessel ashore, the danger inherent in even gently grounding the vessel when afloat, the necessity of tending the boards in difficult conditions, the difficulty of repair, the loss of considerable space within the vessel and on deck, to name a few.

In the absence of fixed keels, the rudders become the deepest projection below the water and fully exposed to damage. The effective draft of a daggerboard vessel is considerably greater when sailing, as the fixed keel is significantly more effective at its shallow depth than the daggerboards would be at a similar depth.

The fixed keels are capable of sustaining considerable damage without affecting the watertight integrity of the vessel. They are easily repaired and provide stable support to the vessel when dry-docked or beached.

It was our intention to build a vessel with rudders that are shallower than the keels for some protection. Unlike daggerboard vessels which have balanced rudders supported entirely from the stocks, the rudders on such a vessel are provided with structural skegs carrying bottom bearings. This relieves the rudder stocks from supporting side loads and the skeg is also capable of sharing in the support of the vessel. The skeg supported rudders are a compliment to the fixed keels.

If the vessel was expected to race occasionally in reasonable proximity to a repair yard, the option of using daggerboards and open rudders would have been considered. Without that requirement, we could not have responsibly marketed them to the ocean going customer.

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4 thoughts on “Daggerboards or Fixed Keels?

  1. I have enjoyed reading the posts on this site. It is great to get more insight into the decisions behind the design and manufacture of the Antares Yachts.

  2. ‘Catamaran Concepts’ is a great idea. It addresses some of the key issues constantly debated among cat lovers.. and delivers in a style that a non techie like me can easily understand.
    I have a question… Would you share your thoughts on ‘In boom’ and ‘In mast’ furling and why you appear (?) to prefer a boom system.

    • Hmmm.. An uncomfortable ‘slip of the keyboard’. My question should have read ‘in mast’ rather than ‘in boom’..But thanks for your reply Ted.

  3. I think this bloke may have been reading your blog.

    http://www.chriswhitedesigns.com/atlantic_cats/a47/index.shtml

    No dagger boards on his latest design, the Atlantic 47. The rational for this design choice is like the first paragraph of your article. Hmmm…

    Also 64′ mast height above the waterline. Might make a more comfortable trip to the Florida boat shows and maybe a little less likely to flip over in a squall compared to her high performance bigger sisters.

    The raised floor in the hulls for the galley and workshop is a nice idea. The engines can be in the center now instead of all that weight in the stern turning a cat into a rocking horse. No dimensions given for all the steps.

    I’m still unconvinced about the bucket of a cockpit out the front. Very wet beating to windward without a dodger and no shade on a summer’s day.

    I think you need to do an article on steering systems as he hasn’t finalised the details there yet. Do you ever say ‘I told you so?’

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