i have a inter 20 i need some help with the spinaker trim when the boat starts to lift do i head up to bring it under control or do i fall of please i would apreciate any info thanks

2032,
It is the opposite to upwind sailing.
Upwind you can head up to depower.
Downwind if the hull is lifted and you head up your looking at making it worse and possibly capsizing.
When the spinnaker is up and you want to settle things down head down.
Get the boat out in light breeses and play around. You'll get the hang of it pretty quick.

can any one tell me the proper mast rake for the inter 20 nacra

Basic setting is 15 cm after the port cover behind the backbeam. To measure, add a short line to the front trap wire. Swing the wire forward to where it touches the front bridal tang. Then swing the trapezeline to the back and hold it against the (centerline) transom of the boat to see where it touches.

That seems a little short. I run from the spinnaker bridal tang, and see where it touches the rudder (placed in the upright position). Usually touches about 1/3 of the way down the rudder. I must have a lot more mast rake.

What's your team weight? I was usually between 325 and 365. Used about 1 3/4" of spreader rake and 700 lbs diamond tension.