Headsail to mast distance?

I haven’t been able to find a good answer to this… What is the optimal distance between the headsail and the mast?

I keep wanting to get the headsail as close to the mast as possible, mainly because the way the sail is cut and to keep the leach parallel to the mast. But I keep being told to move it away. I ask why, and so far I haven’t gotten an explanation, just “because that’s what we do.”

The distance will vary with the size of boat. What you want is sheeting angle. See Lester’s site. He recommends 12 to 15 degrees for the jib and 3 to 5 degrees for the main. On an IOM A rig, a good starting number is 55mm then play with it +/- 5 mm. Also increase in bigger waves.



it happen that I have this drawing in my last design file, it may help ! :

In order to keep the gap close also when the wind increase, the only solution is to slide the full rig forward.



That’s what I’m talking about, not the ‘slot’. I have done what Claudio suggests, but I keep being told that is to close, that it should be a bigger gap.

But why?

Hi Guzz,
I do not knows what to says other of what already told, try to get the rationale from the persons telling you that shall be bigger !