Eric

I have not sailed with the Superwing mast but I have sailed with numerous other masts and was involved in a Tornado mast project with the British Olympic team and the Royal Aeronautical Society in the mid 90's, this mast was similar to the 'wing'. We found a few fundamental things.

1st individual aluminium masts vary hugely in stiffness,

2nd mast rotation had a much greater effect on speed than spreader rake or prebend.

3rd pretty much the same rules applied to all the masts we used.

4th the downhaul is a much more powerfull method of adjusting mast bend (and can be tuned to specific conditions) easily and effectively.

5th the only time that diamond tension made a significant difference to speed was when the windward diamond went slack.

We found that most of the top Tornado sailors were using very different spreader rakes and diamond tension, but were all going along at virtually the same speed.

My advice to you would be to put you spreader rake in the middle of the settings reccomended by the good sailors (Greeg Goodall says 40-65mm I believe.

Then I would set my diamond tension so that when trapezing and with max downhaul the windward wire is just tight, this will make the maximum power for your sail available to you.
I would then forget about spreader rake and diamond tension except for very heavy winds.

I would set mast rotation so that it is at max power (for us it is pointing at the shroud, the tips page on the AHPC site says 50 to 60 degrees, this becomes the base setting and is used in all conditions apart from heavy winds and very light >5 knots windspeed.

Having achieved a max power setting which is used in all wind strengths up to trapezing with full downhaul on, the next step is how to set about de-powering as the wind increases.

During a race this is done by first pulling the rotator towards the middle, (up to 20 degrees off centre), then letting out the traveller (as far as necessary). The guide for how much to de-power is this.

At all times you need to be able to pull on full mainsheet tension without the boat falling over or stuffing into wind and going really slowly. [color:"red"] [/color]

I have highlighted this because it is very important.

If (and sailing in the Bay area this must happen a lot to you), the wind is very strong from the word go, I would let off 2 turns of the diamond tension so that the windward wire goes slack (wires must be heavily taped in or wired in to spreaders if they come adrift the mast will break when you tack). still use max downhaul on this setting but have the rotation in the max power setting(50-60 degrees).

You will find that the sail becomes incredibly de-powered and calms the boat down, it is also very low drag and very fast.

This setting is only for strong winds. and is a 'super depower' setting as fast as it is in heavy winds it is dog slow in medium or light or even quite strong winds.

In very light winds (less than 5 knots) I would set the mast rotation to 80 degrees

give it a try and let me know what you think.

john