Sorry Carl, there are only two categories of 18sq:

Cat. 1 is all up boat weight less than 330 lb
Cat II is 330 lb and over.

There is a website for 18 Squares, Mike Coleman's excellent reference:
http://www.geocities.com/mec_coleman/18square.htm

He describes the class rules &c. for Squares.


There are Lindahl plans available, and there is a guy named Dennis Palin who might be able to help you - Dennis built an ABSOLUTELY gorgeous, fast, Sq, but I think he rather designed it himself. His addy is dpalin@ev1.net

sea ya
tami
ps. The NACRA 18sq is not onedesign, either. The newer models have the 31' mast with laminate higher-aspect sails, the older ones have 30' mast and lower-aspect Dacron sails. Good luck with your endeavour and Welcome To Squaredom. I absolutely love mine!