That is the NACRA 18 square. This is a different boat then are found in the 18 sq. class. It was mainly sailed in USA and the lightest full carbon boats were very close to the A-cats in overall weight even when being over 3 mtr wide. Now the class is dead.

Interesting detail is that Wild Turkey was the first non C-class catamaran to fit a wingsail, it was an 18 sq. boat. The NACRA 18 square never got passed a large roached pinhead sail.

Wouter