What hazard does a fuel leak under pressure create aboard a vessel?

• A. A pleasant aroma.
• B. A harmless leak that dissipates quickly.
• C. An atomized spray that readily mixes with air increasing fire risk.
• D. It only leaks when the boat is anchored.

Answer: (C)

When fuel is under pressure, a leak can send the liquid out as a fine spray instead of a slow seep. That spray mixes with the surrounding air to form a flammable vapor cloud that can travel and spread quickly through compartments. If an ignition source is present—engine heat, electrical equipment, a spark—the vapor cloud can ignite or explode more readily than a non-pressurized leak. So the real hazard isn’t the leak itself, but the easy formation of a combustible air-fuel mixture and the high fire risk that comes with it. It can occur anytime the fuel system is under pressure, not just when the boat is anchored, and it’s not a pleasant aroma or a harmless leak.