Here's a drawing to go with this technical description by grob. This is one scenario where the windward hull just begins to become airborn. If I get a chance, I'll draw one with a tilting rig. The formulas for this (simplistic and 2 dimensional - it's not quite right because it doesn't take into effect the vectors of these forces - more on that later) are as follows.

RM = CoG X D2
HM = WF X D1

If the boat is stable sailing like this (hull not going up or down) then RM=HM. If the hull is rising higher and higher then HM > RM (is greater than). If the hull is falling back towards the water (pointy side still up) RM > HM.