Regarding light air, or should I say very light air, I’ve a different opinion than Mark M. This is how I think of it: the air is moving ever so slowly around the lee side of the sail, maybe the speed of an old arthritic man walking with a cane. At that speed I think it nearly impossible for the molecules to separate themselves from the sail surface enough to cause turbulence. As I understand an airplane wing, it’s the top of the wing which creates the lift, it is a low pressure created by the curvature of the surface. With our sails, it is the curvature of the lee side of that surface. An airplane with a low stall speed has a wing with a lot of curvature. When a jet lands, especially on a short runway, they extend the rear flaps of the wing and angle them downward so that the plane can fly at a slower speed with out falling out of the sky. Am I right Timbo? So I create the fullest sail I can without changing spreader tension or rake because the wind is a fickle thing. I force the rotator toward the side stay, I loosen the outhaul (very important), let the traveler out 4 inches or so, let the sheet out far enough that the leach is open. My jury is out on the down haul, some times I tighten it and it seems to double my speed, but it’s not consistent so I don’t how it works. I get on the lee side and that helps, sometimes I get in the trap and that helps a lot in certain wind. As the hull comes out of the water the boat goes faster and the sail generates more lift and I start floating away from the boat with, seemingly, no way back onto the boat, and I capsize. ( I need to train myself to pull on the tiller in those conditions.) These observations are not from sailing a race course but free sailing, sometimes against Hobie.