I have a Matrix 7.5m and am enjoying it PaulNewc. Whether you rig a sail on the recommended mast or something similar (like a Severne) I reckon you should always treat the measurements as a "guide".
I mostly sail flat water and try and get the most out of my sails but I respect my friends that use wave sails and just rig the same every time (even if they take the piss out of me for fussing about sh!t they don't worry about
)
I had four sails of the same brand and model on the same brand's recommended masts but found significant differences in rigging against the specs. One sail rigged exactly as marked, one needed to be -4cm downhaul, one needed to be +2cm on downhaul. Boom lengths were similarly all over the place.
The panels that are cut are now VERY accurate relative to a decade or more ago. But there are still a lot of areas for variation. Mast curve is a big one, I'm convinced that there is enough variation even based on the mast's rotational position (i.e. where one mark of the mast circumference is to the boom head) to make each rigging slightly different. Let alone the variation from one mast to another.
There has to be variation in the sail material itself.
Then there are simple "actual" variants like a one mast extension that is slightly different measurement wise to another. Booms are the same. As squish says, there is "actual" difference based on your boom height.
I think the moral to the story is to rig
1. to spec
2. to look
3. to feel
Use the Force
