My method for converting a windsurf sail to a land yacht sail.
This has worked better for me and is way easier to do than laying out predetermined coordinates or transferring the bend curve via a template.

Some sails Sailworks, Neil Pryde, work better for this than others. When buying sails I look for the ones with a flatter foot, a straighter luff, 4-5 battens max and grommets for the tack and clew.
I also look for sails that will end up being from a 3.0 - 5.0 when it's done. I'm usually removing 1.0 - 2.5m from the sails.

1.
Select just about any sail.


2.
Rig sail and tighten the piss out of it!


3.
Lay rigged sail on it's side and mark the sail with a sharpie holding it vertical along the sail side of the mast.


4.
Stand rig back up and while still rigged, remove the lower mast sock. Cut stitching along one side by laying a razor blade across the center of the stitching, This is how I usually cut all the stitching during sail prep. Take care here, you don't want to cut into the sail, just the stitching. No "picking" required!



5.
While still rigged measure the height of the clew and mark the new boom position at the tack two inches lower than the clew. The clew on this sail was 48".


6.
Unrig the sail.


7.
The new luff curve marked on the sail.


More to come....