I don't think so. My understanding was that Nacra built the M and M designed inter 18 for the EU for the F18 class that was just starting to grow in popularity (Dart Hawks and Hobie Tigers). They then decided to sell the boat in the USA but the small sailplan was just boring ... So.. just like they souped up the Nacra 6.o to the 6.0 NA to trump the 5.8... they added the Omohundro carbon stick and tried to spice the boat up to convince the Nacra 5.8 NA sailors to flip. This did not work. (Why go smaller) As the story goes... Larry Hartack took a sawsall to the inter 18 bows... added two feet and bingo... the MandM design was now the Nacra Inter20 and the first production cat with a carbon mast. The US market went for the Nacra Inter20 and passed on the F18. Eventually Hobie figured out a way to sell boats without comptips in NA and started selling the Tiger... Nacra followed with the F18 and they grandfathered the small number of inter 18's with carbon sticks into the dealer created NAF18 class. Eventually that organization reformed to be fully compliant with the internationl F18 class.