RedactedNarrative: Operator of vessel 1 had been having overheating issues with the engine. After consulting with a mechanic, the operator began operating vessel 1 in an effort to diagnose/correct the overheating issue. During the operation of vessel 1, the operator smelled the odor of smoke and observed a small fire near the engine. The operator attempted to fight the fire with the fire extinguisher that was onboard. Despite the fire extinguisher being "in the green," it did not work. Subsequently, the fire grew and vessel 1 burned completely.