I have been around Sailboats all my life. For the last 25 years I have built and raced r/c model sailboats. My current question, I hope, can be more of a discussion than just a simple question and answer. Since I am into the design of all aspects of boat and sails. I have a question about the hull and form drag. Most tests of this require the hull in a static position with water running around the shape or computer sim. This is fine for a ship or powerboat that have a straight line propulsion system. This cannot be optimal for sail propulsion. The Sails provide lift and propulsion in a wide angle of directions. This is the reason you would see a sailboat leaning to one side or the other while making headway. The amount of forward propulsion is exceeded by the amount of side force generated by the sail foil. The boat does not sail in an honest straight forward direction. It slips to the side as well as traveling forward. So there cannot be the same optimal hull shape value or calculation of both. It is easy to see the drag effects or flow, of healing moment, in a static position by just rotating the hull over ten, twenty, or thirty degrees. This still does not satisfy my question. I want to be able to design a mono hull that will have a better performance area in relation to side slip or not sailing true to direction. Its like a car rounding a turn and having the tires lose traction and send the car out of position in relation to direction. This would change the effect of airflow around the car to something less than optimal. Well, in a sailboat, this is the dominant relationship between direction and actual position of the boat. The water direction and actual hull direction are not in a direct bow to stearn relationship. I hope someone or two can jump in and provide me more insight and clarity. Thanks.