What is the effect on GZ for a transverse shift of cargo according to stability principles?

In the context of stability principles, the effect of a transverse shift of cargo on the righting arm (GZ) is influenced by the shift's impact on the center of gravity (G) and the metacenter (M) of the vessel. When cargo is shifted transversely, it alters the vessel's stability by changing the position of the center of gravity and, consequently, affecting the righting arm GZ.

When cargo is moved transversely, initially, GZ indeed reduces because the center of gravity moves laterally, which can diminish the arm's length between the center of buoyancy (B) and the center of gravity (G). This reduction in GZ is most pronounced at small angles of heel. However, as the vessel begins to heel and the angle increases, the buoyant force provides an increasing force that helps to restore the vessel to an upright position. Therefore, as the roll angle increases, the reduction in GZ due to the transverse shift of cargo diminishes because the vessels' ability to right itself increases due to the geometry of the stability at larger angles.

Overall, the relationship between the transverse shift of cargo and increasing roll angles explains why GZ reduces initially but this reduction trends to diminish as the roll angle