Which method can be employed to reduce lists caused by icing?

Utilizing cross flooding is a method employed to reduce lists caused by icing because it enhances the stability of the vessel when icing occurs. When ice accumulates on one side of the vessel, it can lead to a significant list—an angle of tilt to one side—which can jeopardize the vessel's stability and safety. Cross flooding involves transferring water from one side of the vessel to the other, equalizing the weight distribution and consequently reducing the list. This procedure helps maintain a more upright position, enabling better control and handling of the vessel in adverse conditions.

Maintaining stability is crucial for operational safety, especially in icy environments, where the weight of the ice can shift unexpectedly. Cross flooding effectively counteracts this shift, allowing the vessel to regain equilibrium.

Other methods listed do not effectively address the imbalances caused by icing. Adding more weight to the top of the vessel would further increase the center of gravity and exacerbate stability issues. Keeping the watertight doors open could lead to flooding and is contrary to maintaining vessel integrity. Vacuum pumping water into lower compartments does not directly counteract the weight distribution issues that arise from icing and might complicate ballast management without addressing the tilt.