Daggerboard position in hull

[waynemarlow]

How does one work out the best location for the leading edge of the daggerboard in a catamaran. Its all very well theoretically saying that the CoE of the sail should align the daggerboard but the sail shape can dramatically alter that position along with rudder position. Any clues from a practical sense would be great.

[PAR]

This is one of the most hotly contested debates in yacht design ever. Unfortunately, there are no set of formulas or number crunching that can nail it down (without an Americas Cup campaign supporting the deal). As you've guessed, the CE and the CLP move around underway, so fixing the optimum location can be tricky. You can resort to the rather unscientific method of an elongated board slot, which can be made right when the proper location is found. This isn't as unconventional as you might expect. It's pretty easy to do and the plans can be redrawn to suit the board location after trials. There are some very general guide lines about placement, but they are rig and hull specific, each having it's own treatment governing the CE/CLP relationship.