You could measure the distance between your rudder pintels or alternatively the port gunwale on the port hull and port gunwale on the starboard hull just to get the distance between the hulls centreline.
Measure between the bow tips then rig the boat and measure between the bow tips. Sheet the mainsail on as tight as you can and measure between the bows again. You will get some tow in, the question is how much.
Just as an indication when I do this to my wood Taipan I get a(15mm) just over half an inch diff. Sheeted on as hard as I can.
I've heard a Hobie 18 can flex as much as two inches but have not measured that myself.
My personal opinion is if you get more than two inches you couldn't call your hulls stiff and may want to explore your options.
Hope this helps.
Phill
I know that the voices in my head aint real, but they have some pretty good ideas. There is no such thing as a quick fix and I've never had free lunch!
