Finding righting moment in the field.

[Brion Toss]

Hello,
You don't have to use people for an incline test, it is just usually the easiest and most fun way to do it. Large vessels use concrete-filled barrels, set aboard with cranes. You should be able to heel your boat at least 10 degrees with humans, but a smaller weight at the end of the boom will work just fine.
Note that the weight of the ballast is not a consideration here; it is the length of the righting moment lever arm (center of gravity to center of buoyancy) that matters.
Fair leads,
Brion Toss