Which of the following is NOT a function of marine pumps?

Marine pumps serve several critical functions on a vessel, including circulating coolant, transferring fuel, and removing bilge water. Each of these functions is vital to the operation and maintenance of the vessel's systems.

Circulating coolant is essential for regulating the temperature of engines and other machinery, preventing overheating and ensuring optimal performance. Transferring fuel is necessary for maintaining the fuel supply to engines and auxiliary systems, enabling the vessel to operate efficiently. Removing bilge water is crucial for safety and stability, as excess water accumulation can lead to flooding and compromised structural integrity.

The third option, which states "increase structural integrity," is not a function of marine pumps. Structural integrity refers to the strength and durability of the vessel's hull and supports, which is ensured through engineering design and material selection rather than through the operation of pumps. Therefore, this option does not align with the intended purposes of marine pumps, confirming it as the correct choice in this context.