I don't know those answers but if you email Goose Marine or Brisbane Catamaran Centre both in Australia you will probably get answers from them, here's some links from Goose's sight
http://www.goosemarine.com.au/content/manual-2003-nacra-F18-Inter.pdf
http://www.goosemarine.com.au/content/Tuning-guide-F18-2003-Model.pdf
good luck


Jeff Southall
Current boats
Nacra 5.8 1703 Animal Scanning Services
Nacra 5.8 1667 Ram Raider
Nacra 18 Square
Arrow 1576