Ed, excellent reply. The insight on sailors doing brilliant things on the race course and crediting it to the wrong reason is great. Finally, due to hard work like yours and Wouter in fighting deeply ingrained misconceptions with facts and logic (which has been very painful for many), many are sailing better and enjoying it more. Although I believe your reply addresses Mark's situation, with an understanding that will help him adjust the info for his needs, his question makes me think about 2 factors in spin (or broad reaching wo/spin) sailing. First: doesn't the small lift off both rudders and boards work against us going downwing? If I understand lift correctly (my mind is boggled that a symmetrical foil can create lift, when I came to understand this at a landsailing event, I felt as though I had a religious experience) the lift from the underwater foils is pulling us windward and we want to go leeward. Yet my experience and that of the Tornado sailors indicates you are at least no worse off to leave everything down and probably better off. (Seems like individual boat design should make a large difference on whether to pull up boards. My P-19 doesn't like to slip sideways even with all boards up, but a N5.8 slips very easily with boards up, yet a P-19 is a little faster downwind than a N5.8. I'm puzzled because both boats have very similar length/sail area but have very different hull shapes. I had imagined that the N5.8 could slip sideways at least half as fast as its forward speed allowing it point a little higher giving it killer apparent wind and very deep sailing angles)

Second: The mast raking to get the rudders working harder should cause the rig to have less power downwind, which should be more important than getting the rudders working and upwind performance. All of this makes me think I may not have the proper understanding of the forces at work, UNLESS the answer(s) lies in raking the mast less than x degrees makes minute changes to the sail area/ lift factors and makes good improvement in balance and drag and possibly lift in another plane.