On most commercial cargo vessels with a relatively small crew size and few users of the potable water system, how is the potable water system pressure maintained?

Correct Answer: Option A — Cycling the potable water pump on and off by the action of the potable water hydro pneumatic tank pressure switch in response to system demand changes.

Potable water systems utilize a hydro-pneumatic tank to maintain pressure. A pressure switch monitors the air-water interface; when pressure drops due to demand, the switch starts the pump. Once the tank reaches the high-pressure setpoint, the pump stops, preventing constant cycling and maintaining stable system pressure for the crew.