Caravelle 16 - daggerboard vs centreboard

markus · Post by **markus** » Fri Nov 03, 2006 6:25 am

Anyone have any thoughts on replacing the centreboard with a daggerboard on the CV 16? I guess this is directed mostly at Jacques (but anyone is welcome to comment).
I've always liked the simplicity of daggerboards on small sailing vessels.
Easier to build, smaller box (housing) in the cockpit, no moving parts and truer, more efficient foil relative to the water flow at different raised positions.
The downside is when not in use it has to be stored in the boat and if you ground it might damage the hull (although in familiar waters this shouldn't really be a problem).
I used to own a Hobie 18 so I got pretty used to daggerboards. Jacques' centreboard design for the CV 16 is neat and elegant and self-storing but I pose the question?

chrisobee · Post by **chrisobee** » Fri Nov 03, 2006 5:23 pm

The CV 16 plans include an option for a daggerboard.

markus · Post by **markus** » Sat Nov 04, 2006 4:09 am

Yes actually, there is a diagram and brief 9 point description but no dimensions on B102/4 Appendages (or anywhere else). I also seem to be missing a diagram & dimensions for the fore deck and nesting for frames & transoms.
I'm a way off that stage of construction since I only received my plans last week, but any info on the above would be appreciated. Also, I don't quite understand how the rudder head goes together? Obviously the blade articulates inside the bottom part of the rudder head, but how it all goes together is not clear to me.
I have been busy going to school on pages and pages (years) of posts on this forum as well as the tutorials, and am pretty clear on most stages of stitch & glue. I have read plenty by you and other experienced CV 16 builders - no doubt I will need more advice over the next few months. Any help with the above would be appreciated.
Regards, Markus

chrisobee · Post by **chrisobee** » Sat Nov 04, 2006 6:46 am

If I were to do the dagger board option I would derive the dimensions from those given for the centerboard. The only bit there that is of grave importance is the shape of the foil under water, so keep the same shape as the centerboard. The dagger board will need to be longer than the centerboard. Determine the height of the dagger board case from the height of the centerboard case. Determine the width from the centerboard case. If anything it should be a bit tighter. Take the length of the dagger board case from the dagger board. Again you will not want a lot of slop.

You will want to take the dimensions of the fore deck from the hull. The shape fo the foredeck will depend on how the ply bends around the frames. Likewise the seat tops and fronts. Use cardboard to make a pattern. Fit them to your hull.

I cut both transoms and both frames from a single piece of 3/4" ply. There is no nesting but it is also not a tight fit.

The rudder has to cheeks above and the foil below. The rudder pivots between the cheeks. It needs to kick up to the back in the event it hits something submerged. The plans only show one of the cheeks. The cheeks are outside, the rudder is inside. Does that help?

markus · Post by **markus** » Sat Nov 04, 2006 6:02 pm

Yes, that helps a lot - thanks. I am an experienced sailor but I'm no boat builder. I'm not sold on the dagger board yet, just mulling over the option. I do like good windward performance and I wondered with the centreboard (even though weighted) it is not locked down and may move fore and aft (bounce) on the pivot when sailing fast (planing - is the CV 16 capable of planing?) or bouncing over chop, thus effecting performance?!? A dagger board is of course, "locked" in place. What do you reckon?

I'm puzzled - you said you cut both transoms and both frames - aren't there 3 frames? You also chose extra stiffness 'cause you cut them all from 3/4" (20mm) ply. Do you recommend this? The cardboard template is a great idea - simple & effective. I'm not the handiest guy - this project is a 1st for me.

So do the rudder head cheeks have battens (spacers) between them at a width just greater then the width of the rudder blade? Are these battens around the entire perimeter (profile) of the rudder head (except the bottom, of course), epoxy glued together?

chrisobee · Post by **chrisobee** » Sat Nov 04, 2006 8:01 pm

I do not expect the CV16 will plane. The bottom has a lot of rocker.

I made the Three frames and both transoms out of 3/4 because I bought the sheet of ply and wanted to use as much of it as possible. I also wanted to reinforce the rear transom for use with a small motor.

So do the rudder head cheeks have battens (spacers) between them at a width just greater then the width of the rudder blade? Are these battens around the entire perimeter (profile) of the rudder head (except the bottom, of course), epoxy glued together?

The tiller will be the top. You should probably have some sort of bracing where the pintles attach. You probably don't need anything on the other face. There is a great deal of the rudder material between the cheeks so I don't think that extra bracing at the trailing edge of the cheeks. I have not yet constructed the rudder and I have yet to apply a great deal of thought to the problem.

I suspect that the dagger board will out perform the center board. However the center board has other advantages. It kicks up if it hits something.

I have yet to sail anything. My build has been on hiatus for a long time. I have a had a few rides, that's it. This summer I went for a ride on a cat boat at Mystic Seaport. I had a great deal of fun.

markus · Post by **markus** » Sat Nov 04, 2006 10:34 pm

OK, thanks for your help.

ks8 · Post by **ks8** » Thu Nov 06, 2008 12:29 pm

Two years have gone by. Are you sailing?

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