Question 7Safety & Environmental - 1st Asst/Chief

The correct answer is A) free surface effect. When the amount of liquid in a ballast tank changes, it has the greatest influence on the free surface effect. The free surface effect refers to the impact of free-moving liquid in a tank on the vessel's stability. As the liquid level in the ballast tank increases, the free surface area also increases, which reduces the vessel's righting moment and makes it more susceptible to heeling or capsizing. The other options are incorrect because they do not directly address the primary impact of the changing liquid level in the ballast tank. The virtual rise in the center of gravity (B) and the value of the moment to trim 1 inch (C) are not the primary factors affected by the increased liquid in the ballast tank.