Navy DCU Indoctrination Practice Test 2026 – Comprehensive Exam Prep

The distance at which a portable CO2 extinguisher can effectively reach and blanket the fire is what this question tests. CO2 works by displacing heat and oxygen at the base of the flames, so you want enough distance to aim the jet at the base and keep a steady sweep to cover the fuel. About 4 to 6 feet gives a practical balance: close enough to deliver a concentrated plume to the fire’s base, yet far enough for the gas to spread and blanket the area rather than dissipating before contact. If you stand farther away, the jet tends to dissipate before it reaches the fire, reducing effectiveness; if you’re too close, you may not achieve full coverage and can waste the extinguisher’s reach. Therefore, 4–6 feet is the best range.