Mark: This forum is to sailing what ground school is to flying. In other words, because of space limitations etc, I deal with the basic principles that apply to sailing a sail boat be it a masthead or fractional rig. Once you understand the principles of draft depth, draft position, twist and angle of attack and how the sail trim controls effect those item you apply them to either a dingy or a 40 footer. The basic settings I suggest on my SAIL TRIM CHART may be right on for some boats and need to be tweeked for another one. Either way, you will be in the ball park. The great thing is, once you understand how all this stuff works, you don't need the chart anymore. You've arrived!!