What happens when the center of gravity shifts?

When the center of gravity shifts, it influences overall stability, making this answer correct. The center of gravity is a critical factor in determining a vessel's stability. When the center of gravity moves, it affects the metacenter and the righting arm, which directly influences how well the vessel can recover from heeling or listing. A higher center of gravity can lead to decreased stability, while a lower center of gravity can enhance stability.

In contrast, options regarding increasing cargo space or improving vessel appearance do not directly relate to the effects of a shifting center of gravity. A shift in the center of gravity usually does not create extra cargo space; rather, it might indicate that cargo has been moved or improperly stowed, which could harm stability. As for vessel appearance, while the aesthetic might change due to loading conditions, the primary concern with a shifting center of gravity is its impact on the vessel’s stability and safety in navigation. Additionally, the claim that a shift has no notable effect contradicts foundational principles of stability, which emphasize the importance of center of gravity in maintaining a vessel's safe operational integrity.