Why is it necessary to extend ventilators of gasoline powered vessels to the bilges?

Correct Answer: Option A — To remove fuel vapors which are heavier than air

Gasoline vapors are significantly denser than air and naturally settle in the lowest parts of the vessel, such as the bilges. Extending ventilation ducts to these low points is a critical safety requirement under 46 CFR 25.40 to prevent the accumulation of explosive mixtures that could lead to catastrophic vessel fires.