I will concur..
As a helm that was heavier than my crew sailing the nacF18 [which is a bitch downwind in a breeze], i went through a spell of doing the trapezing downwind - OK in a straight line, but the corners did get a bit messy! experiment abandoned. problem solved by purchase of infusion!
Can you elaborate on the Nacra F18's downwind behaviour? I buried the bow a couple of times under spinnaker recently, in about 20 kts of wind, much to my surprize. I'm new to this boat, and I've not had this much difficulty with the other spin boats I've driven. Thanks!
Dave