Ed,

The spin will need constant trimming but in very small increments. I know I am in the groove when I am having to move no more than 6-8 inches to keep it full and flowing.

If you find your apparent switching, especially to the point of coming so far forward as to collapse the sail, you are either comming up way too far or waiting to bear off too long. You want to remember that you are comming up to get additiional hull speed, not necessarily to try and fly the hull. As you are learning, try to keep the ratchets off so you can feel the sail. When rounding up you want to only go up as far as where you are feeling increased pressure in the sail. At this point hold it steady and try very small increments of up and down to judge relative hull speed and try to maintain the pressure in the sail. Adjust your crew weight accondingly then depending on the conditions so that at this point you can get the windward hull up (if it is not too gusty or wavy and you feel comfortable)

This is very critical when the wind is lighter. When it is blowing it is very easy to feel the hull speed change with the tiller. When it is light is is very easy to way over steer and go very slow. When it is light downwind my crew tells me constantly how to drive based on the pull on their sheet. Cat sailing is all about maximizing hull speed. Whe it is right, you are fast and the apparent wind will stay very steady even if the conditions are not.

M