Transverse ship stability depends on the relative positions of the center of gravity (G), the center of buoyancy (B), and the transverse metacenter (M). When waves or wind induce a roll angle (θ), the submerged hull shape becomes asymmetric, causing the center of buoyancy to shift laterally to B'. This creates an internal righting lever arm (GZ = GM · sin θ) that produces a restoring torque returning the vessel upright, provided the metacentric height GM is positive.