What should be ensured when inspecting a freshwater system?

To ensure a freshwater system is reliable and effective, it's crucial that it can function properly on both pump and city water hookup. This capability allows for versatility in various situations; for instance, when a vessel is at dock, it can connect to city water, whereas when out on the water, the system should still function optimally using the onboard pump. This dual functionality indicates that the system is well-designed to adapt to different water supply scenarios, ensuring consistent availability of fresh water regardless of the circumstances.

Other options may seem relevant but do not comprehensively address the critical operational integrity of the freshwater system. Relying solely on bottled water would not provide a sustainable solution for all situations, and visible leaks could lead to serious issues, but their presence doesn't necessarily indicate the overall functionality of the system in diverse water supply conditions. Maintaining a constant temperature might be important for certain applications but is not a fundamental requirement for the basic operation of a freshwater system.