To minimize the hogging effect during hot weather, what precaution should be taken?

To minimize the hogging effect during hot weather, running water over the deck during daytime is an effective precaution. Hogging is the upward bending of a vessel's hull that can occur when the temperature rises, causing the hull material to expand. This thermal expansion of the hull can lead to stress and potential hull deformation.

By running water over the deck, the temperature of the hull can be lowered, preventing or reducing thermal expansion. The cool water helps maintain a more uniform temperature throughout the structure of the vessel, mitigating the risk of hogging. This proactive step can help ensure that the vessel remains stable and structurally sound in fluctuating temperatures.

The other options may not address the specific issue of thermal expansion directly. For example, reducing the vessel's speed does not influence temperature, while ballasting the center tanks or reducing the tonnage loaded in the center focuses more on the weight distribution rather than the material's thermal response. Therefore, the most effective method in this context is indeed running water over the deck to control the temperature and prevent hogging.