Builders' Forum

RE: Skerry CLR?

 » Submitted by John, CLC - Fri, September 26 » 3:34 PM

If you count the skeg---and you should---the Skerry's CLR is a bit aft of the daggerboard. 

There are byzantine formulae, beloved of armchair sailors, subject to eye-rolling by designers, used to position sails and foils on small craft.  The best known is that the CE should be positioned 10% of the waterline length forward of the quarter-chord of the fin.  That works pretty well, but only for beamy, shallow-bodied hulls with transoms and prominent fins or centerboards---which describes an awful lot boats.  Certainly that's the formula I applied to our small craft that fall under that description:  the Passagemaker, Jimmy Skiff, and PocketShip.

In my experience, however, narrow double-ended boats don't subscribe to that formula at all, and tend to have pretty neutral helms no matter where the fin is placed, within reason.  The Skerry, at least once it's moving, has almost no helm, or just a touch of weather helm, as is desirable.  If you calculate the geometric center of area of the whole underbody excluding the rudder fin, you get an 8% lead of CE over CLR.

RE: Skerry CLR?

 » Submitted by Kristofer - Sat, September 27 » 9:23 PM

Thanks a lot for the considered reply. I appreciate it. -Kristofer