1. 一つの線が平衡状態にある船体の浮心を通り、もう一方が船が一つの方向に傾く時に船体の浮心を通る2つの垂直線間の交点(the point of intersection between two vertical lines, one line through the center of buoyancy of the hull of a ship in equilibrium and the other line through the center of buoyancy of the hull when the ship is inclined to one side)