On a tanker vessel, what is the required combined capacity of the inert gas generating system as compared to the total capacity of all the cargo pumps which can be operated simultaneously?

Correct Answer: Option D — 125%

To maintain a safe, non-flammable atmosphere during cargo discharge, 46 CFR 32.53-30 requires the inert gas system to have a capacity of at least 125% of the total cargo pump capacity. This margin accounts for gas losses and ensures the tank pressure remains positive throughout the entire discharge cycle.