Hi Fritz, It has been a while but the Inter 18s that raced in Michigan were known to be relatively slow in light air and more competitive in a breeze. We used to beat them in lighter air boat for boat with the Hobie 18. Of course, that was back in the days when most cat sailors also did not know how to use a spinnaker. Like you described, I remember the excuses being that the rounded hull bottoms really slapped the waves and bounced around a lot in the Lake Michigan chop. The Hobie 18 hulls were fairly thin and sliced the waves better. I still think that if you upgraded the rig and sails on a Hobie 18 platform that it would surprise a lot of people with its performance! I briefly raced a Hobie 18 with a full, mylar flat top mainsail (only change) that beat Hobie 20s boat for boat in light to medium air.

Mike