CG conversation, whats a good starting point for 36 Catamaran?

[Camo]

I have a 36 Catamaran that is in the middle of a build, I read that 1/3rd from the rear is a good starting point, but from where do you measure from, the back of boat or the back of the sponses. This will be a dual moter build on 5-6 S. I need to learn more about CG. Little help.

[Tom M]

If the sponsons end at the transom it shouldn't matter. If there is transom overhang over the sponsons then it makes a difference. If they end at the transom, use transom. I believe if there is overhang, to use the back of the sponson, or so I read at one point

[Fluid]

Correct, CG measurements are taken from the rear of the actual planing surface. The optimum CG location depends on hull design, weight and speed but usually ranges between 31% to 34%.


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[Camo]

Thanks a lot! So I will set it at 12" from the back of the sponson on my 36" catamaran..