Righting moment calculations
 

I've noticed that most physical righting moment test are done with a mast on. Can this method be used without a mast, as a part of a method to determine new rigging?

Mast
 

Hello at last,
Because the mast has weight, it affects stability. Because it has height, it affects it more than something the same weight that is shorter. With the mast in, as the boat heels the portion up highest goes furthest outboard, contributing to further heel. The short form is that with the mast out the boat will be stiffer than when it is in. How much stiffer depends on how heavy the mast is. This is why we worry about rig weight.
For the purposes of determining standing rig scantlings, just err on the conservative side, unless you plan to install an absurdly heavy stick, in which case you have other problems.
Fair leads,
Brion Toss

perfect, thanks