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Keel & centerboard modifications

PostPosted: Thu Nov 18, 2021 4:47 am
by Arjen
Still on the drawing board but allready some ideas for a modified keel and centerboard voor Alu Pocketship V 2.0

I wanted to get rid of the keel for a few reasons: Better balast/weight distribution, less drag, easier trailering/beaching/drying out and even more agility.
As the retracted centerboard sits in the keel I had to rethink the size and shape...

Some first thoughts:
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Re: Keel & centerboard modifications

PostPosted: Thu Nov 18, 2021 1:56 pm
by buckeye
I'm no boat designer but I've sailed a lot of small boats

I am impressed with the handling of this boat with such a short waterline.
I expect it has a lot to do with the long stub keel.
I recommend keeping it.

Re: Keel & centerboard modifications

PostPosted: Thu Nov 18, 2021 3:05 pm
by Arjen
A long keel adds to directional stability in the first place.
If you compare a long keel with a "slim" deep keel (or centerboard) of the same area it is less effective regarding to slipping.
This is because the effect of the keel is primairily in the leading edge of the keel.

The pocketship hull seems bit hybrid. It looks like it started as a sloop hull with a straight keel under the entire length of the hull.
If the pocketship had its keel extended over the entire bottom it probably would not need a centerboard at all.

For ocean going sail boats it is recommended to have a so called full keel or modified full keel. It is slower but more comfortable (as for directional stability in running waves)
For a better performance (speed and better windward sailing) a slim keel and rudder works better.