What safety precaution should you take while filling the fuel tank of a gasoline-powered boat?

Keeping engines, motors, and fans turned off while filling the fuel tank of a gasoline-powered boat is an essential safety precaution because it minimizes the risk of igniting fuel vapors. Gasoline vapors are highly flammable and can easily ignite if exposed to any source of sparks or flames, including those produced by operating engines and electrical devices. When the engines are off, the likelihood of creating a spark from the ignition system or from electrical components is significantly reduced, creating a safer environment during the refueling process.

Turning on the air conditioning, keeping lights on, or having a fire extinguisher handy may not directly contribute to minimizing ignition risks during refueling. While having a fire extinguisher on board is a good safety practice in general for emergencies, it does not eliminate the danger posed by operating equipment that could cause an explosion or fire during fueling. Therefore, the most effective precaution is to ensure that all engines, motors, and fans are completely turned off before starting to fill the fuel tank.