The EPO rudders I am presently using were sold to me "stock" on my old Hobie 18. The 18 is gone, but the EPO rudders stayed and are proudly on my Wave. So, my Wave must be STOCK since they were sold with a Hobie boat.

Considering these crazy rules that favor the 16 (and one might note that all the rules for all the classes are determined at the National Meeting, held during the H16 Nationals -- perhaps the reason for the demise of the TheMightyHobie18, once my favorite boat) you are referring to Matt, good heavens, isn't it obvious why the IWCA is where it is.