How do changes in fuel levels impact vessel stability?

Changes in fuel levels primarily impact vessel stability by altering the center of gravity. As fuel is consumed or added, the weight distribution on the vessel changes. An increase in fuel decreases the ship's center of gravity if the fuel is located low within the vessel, which can generally improve stability. Conversely, if the center of gravity rises due to the movement of weight (like adding fuel on a higher deck), it can make the vessel more susceptible to external forces, potentially causing issues with stability.

Additionally, as fuel levels change, it can affect the overall weight and buoyancy of the vessel, further contributing to its stability dynamics. Therefore, monitoring fuel levels is crucial for maintaining the vessel's stability throughout its voyage.

Options that discuss speed, cargo allowance, or navigation time do not directly relate to how the center of gravity is influenced by changes in fuel levels and their effects on stability.