If item "1" shown in the illustration is a compound gage indicating zero psig and the water level in the bilges is one foot high, the unit is __________. GS-0153

Correct Answer: Option A — not turned on

A compound gauge reading zero psig while the unit is supposedly operational indicates a lack of system pressure. If the bilge pump is running, the gauge should reflect positive pressure; therefore, a zero reading confirms the pump is not engaged or the system is not actively processing bilge water.