M_Boats: Potter and Catalina

Had an interesting conversation this afternoon, with couple of boat owners here in Mission Bay. One person works in the boat yard a another claims to be into marine and navel architect designs. So here goes, this is not my statement and I have never heard this before. "That most if not all the keel - centerboards have less than a 10% increase in windward performance compared to the board being up or down, but the real benefit to lowering the centerboard is the lower the weight for ballast in carrying full sail, or for self rescue" Is any one a designer of sailboats listening, I would like to know how true that statement is. This statement does not include pure centerboard or dagger board sailboats