Tools required:
Long tape measure
Short tape measure
Straight edge - (a Sail batten is ideal)
Thin line
Rig tension gauge

Step by step guide

1. Spreader length and defection - With mast flat on the floor set the spreaders to the following measurements:
   Length (measure from mast wall to shroud) 1' 8"
   Deflection (measure from luff groove to straight edge across spreader ends) 8"
   
    
2. Stand the mast in the boat with the shrouds in position. The mast should be hard up against the heel pin but without the tabernacle pin in position.
   
    
3. Pull up the genoa and pull on the required rig tension. This should me measured on the shroud with a tension gauge. To achieve the necessary tension a highfield lever, muscle box or cascade system must be used.
   Desired rig tension 340lbs
   
    
4. Measure the mast rake. Pull a tape measure up to the top of the mast.
   Lower or raise until 19' 3" comes to the middle of the gooseneck black band.
   Fix the halyard at this point.
   Take the tape measure to the back of the boat (under the traveller if fitted) and read this measurement. If there is no traveller, read to the top of the cut out on the transom for the tiller.Desired mast rake 23'5" - 23' 7" (as a rough guide, the more upright the mast the faster the boat will be off wind, this though will be detrimental to your upwind speed. Achieving the correct rake must be a compromise)
   Problems:
   Rake too much (mast to far aft)
   Move the pins in the shroud adjusters up.
   Rake to little (mast to far forward)
   Move the pins in the shroud adjusters down.
   If you do have to move the shrouds, go back to item three and start the process again.
   
    
5. Does the tabernacle pin fit through the hole without touching the sides of the mast.
   If not ask yourself the following questions:
   When you push the pivot pin through the hole, does it jamb against the front or the back of the mast?
   Back - Move the pin in the mast foot forwards
   Front - Move the pin in the mast foot forwards
   (If the holes in the mast foot give too bigger an adjustment, use a five pence piece to give fine adjustment).
   
    
6. The final thing to check is mast bend.
   Pull the main halyard tight against the mast next to the gooseneck. Now measure from the back of the mast to the halyard at spreader height.
   Desired measurement - 1½"
   Problems:
   Too little bend - move the spreaders back
   Too much bend - Adjust the spreaders forward.
   (Note - only small adjustments will be required.)
    

If you do have to alter the spreader positions it is recommended that you go back to the start and recheck all measurements.