Go to the webpage :
[url=http://www.geocities.com/f16H...f16HPclass/Tech_genaker_mast_setups.html [/url]
And see how you can lower your spi hound by just drilling two holes in the mast track (NOT the mast itself) and making a hound from a piece of high tension line and a ring or shackle.
You can keep you 21 sq .mtr hound and ADD a string hound for the probably shorter luffed 17 sq. mtr. spi.
It really works well. F18's Tornado's and my own boat have used this system for succesfully for a while now.
Now I HAVE the Goodall fax where AHPC advice the hound height BUT each time I look for I can't find it. And when I don' look for it I seems to stumble into it from time to time.
Anyways, I do remember that the AHPC adviced height was only a fraction of an inch less than the hound height used in the F16 HP class rules which is 7,5 mtr. = from the top of the forebeam. 24 ft. 7 inches
I can't answer the other questions. I'm sure others can
Good luck
Wouter