What is the primary reason for keeping the potable water tank above the bilge?

Keeping the potable water tank above the bilge is primarily intended to prevent contamination of the water. When the potable water tank is situated above the bilge, it minimizes the risk of pollutants and contaminants from the bilge water entering the potable water supply. Bilge water can carry oils, fuel residues, and various contaminants that, if allowed to mix with the drinking water, could pose serious health risks.

The positioning of the water tank is a crucial factor in maintaining the quality and safety of the water onboard. By ensuring that the potable water supply is at a higher elevation than the bilge, any potential backflow of contaminated water into the drinking water system is effectively avoided. This practice is an essential aspect of marine safety and sanitation standards, crucial for the health of everyone aboard the vessel.