radar on the mast

[MarkG]

I found this iin 'Seaworthiness The Forgotten Factor' by C. A. Marchaj. (Equation 20A, page 128).

Tn=6.3(SQRT(Ir/(GM*displacement)))

Tn is the natural period of rolling
Ir is the mass moment of inertia, not the area moment of inertia.

Adding a weight (mass) on the mast increases Ir. But calculating Ir requires knowing the location of every mass on the boat, which is not likely to be known. So this formula probably won't help much.

Mark Gardiner