I looked into this when they changed the rules a few years ago.Yaching NZ required you to supply a certificate showing to the inspector that your boat complies with any one of the alternatives (Stability Index, STIX Value, Positive Stability or pull down test result). I was unable been unable to locate such information on the internet, and this is the problem with all boats that are not a really common NZ design, or a modern design with a designer able to supply the info.. Most of the longer races here in Nelson/Tasman Bay are cat 4 which only require a declaration which side steps the problem. Obtaining an ORC rating somehow also solved the problem, which is not supposed to be that hard, I never understood the details of that.