Reproduced by kind permission of Richard Estaugh, Speed Sails

MAST RAKE
21' 10" (6654mm). Attach tape to main halyard and measure 18' (5486mm) to black band at gooseneck level, then swing the tape to the transom and measure to the top of the transom (using 400lbs/180kg of rig tension).

RIG TENSION
Light - 350lbs/160kg (measured on shroud)
Medium - 400lbs/180kg (measured on shroud)
Heavy - 440lbs/200kg (measured on shroud)

SPREADERS
Length - 360mm
Deflection - 155mm

PRE BEND
3/4" (19mm) with no Genoa on the boat, once the Genoa is hoisted and the rig tension applied at 400lbs/180kg the mast should be straight.

MAST HEEL
2835mm back of transom to bearing surface of the back bolt in mast step.

HOW TO ACHIEVE THESE MEASUREMENTS

SPREADERS
The length of the spreader is taken from the side wall of the mast to the shroud. The deflection is taken by placing a straight edge from shroud to shroud, and then measuring from aft face of the mast to the straight edge.

MAST
The measurement of 2835mm is taken through the transom flap from the back of the transom to the bearing surface of the back bolt. Make sure the tenon sits snugly in the mast step. Now hold the mast about 1/3" to 1/2" (9mm-13mm) of the way out of the gate, then attach the shrouds. This will get you very close to the correct rake. (Make sure that you have a very strong mast gate). You should now have about 3/4" (19mm) pre-bend. Measure this by pulling the main halyard tight and hold it next to the mast at the gooseneck. The distance at spreader height between the main halyard and the back of the mast should be 3/4" (19mm) .
Now hoist the Genoa and apply 400lbs/180kg of rig tension. Measure this using a rig tension gauge on the shroud at the same height each time.

If you now pull the main halyard right to the gooseneck there should be virtually no gap (Straight Mast).

MAST RAKE
This is where it is important to remember that the measurements are only a guide as the rake measurements can vary from 21' 9" to 21' 11" (6628 - 6679mm).

It is also important to make sure to set the tape measure to 18' (5486mm) at the lower black band (by using the main halyard rack) every time you check your mast rake.

RIG TENSION
This should be easy to adjust. The best place to locate this control is on the centreboard capping. The tension should only be adjusted according to changes in wind strength and not according to the leg of the course.

The majority of sailing will be done with a tension of 400lbs/180kg (Force 2-4), below a Force 2 reduce the tension to 350lbs160kg and in almost a flat calm condition down to 300lbs/136kg. Above a Force 4 increase by a small amount to 440lbs/200kg. This does put a lot of strain on the boat so if you have an older boat be careful. If in doubt use a lower rig tension.

Please bear in mind that this is only a guide and some boats/helmsman will require slightly different measurements.