NACRA was originally concieved as a professional racing circuit on 36' beach catamarans. The racing circuit didn't get very far, but they did build several one-design 36' boats for the North American Catamaran Racing Association. The story (myth?) that I heard is that the designer of the boat, Tom (I can't remember his last name) fell asleep on one of the 36's as it was cruising along at about 30 knots. After his nap he decided that, although the racing circuit was a flop, the hulls gave a very smooth ride. Smooth enough to let him sleep at a high velocity. He then decided to make a 1/2 scale model of the boat makeing it 18' feet long. Some marketing genius convinced him that an 18' boat wouldn't sell, so he lopped 1' off of the bows & came up with the NACRA 5.2. Named for the racing association of its origin and its 17'length in meters. The boat was smooth, but had a tendency to nose dive in a breeze.