Which of the following is a consequence of having slack tanks on a vessel?

Having slack tanks on a vessel can lead to an increased risk of capsizing. When the tanks are slack, meaning they are not filled properly and contain a large volume of liquid that can slosh back and forth, the vessel's stability is compromised. This movement of water alters the center of gravity, which can significantly affect the vessel's metacentric height and overall stability.

As the liquid in the slack tanks shifts, it creates a situation where the center of mass can move unexpectedly, leading to rolling motions that may exceed the vessel's limits. In severe cases, this can cause the vessel to heel over to a dangerous angle and potentially capsize, especially in rough sea conditions.

Having appropriately filled tanks, often referred to as "full" or "trimmed," provides a more stable center of gravity and reduces the risk of capsizing by allowing the vessel's design to maintain its intended balance and performance during operations.