Just started sailing Supercat 19 and the old owner didn't have the spec. for the retrofit spreader. I did a quick pluck of the cables- which seemed to be about the same tension, but does anyone know light and heavy air specs?

Thanks John

The folks at Aquarius answered the question well - which was about diamond wire tension.

"I am assuming that your are talking about diamond wire tension? The SuperCat 19 rig was designed to be adjusted depending on wind conditions. In light winds (no trapeezing) the wires were adjusted by hand so they were taunt. As the wind conditions picked up the wires were loosened so the mast would flex more and depower as necessary. When loosening the wires care is taken so they are both adjusted equally. To verify that they are equal you can simply press the wire against the side of the mast and see how far up the mast you can make the wire touch. Both sides should be equal. Remember not to loosen the wires too much, since you still need them to support the mast. If I recall correctly, a save measurement is 10" up from the bottom of the mast extrusion. Ie: If the highest point of wire contact is less then 10" from the mast base, then your ok.
Hope this helps."

That covers it- I'm glad I didn't go with my gut instinct to tighten in higher winds.

The above advice applies only if you have a straight spreader that is perpendicular to the mast. The reverse should be true for spreaders that are raked...i.e. swept aft. The difference is that raked spreaders allow you to induce pre-bend in the mast by tightening the diamond wires. More prebend makes for a flatter mainsail desirable in windy conditions. Less prebend (looser diamonds) makes for a fuller mainsail desirable in lighter conditions.

I will have to take a look I can't remember if it is strait or swept back- That's an important difference they didn't mention in the response- Thanks a Lot

Do you have the supercat 19 or Supercat 19X or 19XL? The standard 19 has the 28 ft 9 in mast which has spreaders that are not swept back. The Supercat 19X and XL have a mast that is 33 ft long with swept back spreaders. This mast is a prebend. I happen to have both rigs for my 19.
On the prebend (19X) Adjust to your preference. If you find it overpowered reduce tension to where the mast is almost straight or straight. (I found this to be the case on mine.) If you want more power tighten on the diamond wires. Mine came from the factory with about 8 full turns on the turnbuckles.
On the standard 19 mast I have mine snug where I can go up about a foot and touch the wires to the mast.
I hope this clears up a little of the mud. I usually sail with the smaller rig. The boat handles better in the rough stuff especially single handed...