Rolf,

I was racing a Category II 18 Square in Traverse City when Jon Lindahl on LCD (stands for Lindahl Catamaran Development) defeated Craig Riley on Wild Turkey. The conditions were light that year and Jon beat Craig by forcing Craig to tack often, if I remember correctly. The rigid wing forced Craig to go behind the sailplan on tacks and gybes and Jon was quicker going under his boomless rig. This allowed Jon to keep putting LCD's bad air onto Wild Turkey, forcing Craig to tack. Tactically, Jon raced like it was a match race with Wild Turkey, and never let Riley get away. The regatta was close, but Jon Lindahl won the North Americans that year on LCD.

To be completely honest, Lindahl had been doing extensive development of his mast and sails with the ability to test against a fleet of at least six 18 Squares at every regatta, one of which was very close in speed to Jon on LCD. Jon must have gone through 3 or 4 masts and more mainsails in the two years leading up to the 1987 North Americans. Wild Turkey had been launched in 1981 and had been undefeated until that regatta in September 1987. I don't think Craig had done much to improve the boat, and in talking to him, there were not as many regattas for him, especially not the number of 18 Squares to test against.

The traveller on LCD had a center of radius behind the mast and the ends were higher than the center. This eliminated the need for a boom, allowed use of a decksweep mainsail (small notch in the trailing edge for the skipper to pass through on tacks and gybes) and resulted in Jon setting the mainsheet upwind and then just letting out the traveller to go off the wind or downwind. The design of the traveller track induced twist and inhaul in the mainsail. The thought at that time was that a decksweep mainsail would make the available sail area (18 Square Meters including spars) more efficient by not allowing the wind to go underneath the sail and creating an endplate effect. Jon designed LCD after competing in A Class for number of years, wishing to take advantage of the added sail area and unlimited width which the 18 Square Meter Class offers.