Long story short I am attempting to make a 7.5 in Portuguese style dinghy that I found free whole designs for online called the farra belle. I asked a person who sells sails which one I should get but they said that what I should be focused on is where it is I need to mount the sale and whether or not it's balanced. something about the center of something? Like where the sail I think would have the greatest maneuverability? How do I figure that out? Like how do I do the math there? Also, I was going to essentially put a piece of wood straight down the center to make a keel the length of the dinghy that's about 6" total the whole length. Would a dagerboard be better for stability? Like just one center of piece of wood mounted on the center? Sorry idk what I'm really doing here with some of this.