What is the function of a fire extinguisher on a boat?

A fire extinguisher on a boat serves a critical safety function by putting out fires and ensuring the safety of all onboard. Boats can be susceptible to fire hazards due to fuel, electrical systems, and other combustible materials. In the event of a fire, a fire extinguisher provides the immediate means to address the situation, potentially preventing it from spreading and causing more significant damage or injury. Having a readily accessible and functioning fire extinguisher is vital for any vessel to enhance the safety of passengers and crew, as well as to protect the boat itself.

Other options, while they might touch on safety or emergency protocols, do not accurately describe the specific role of a fire extinguisher. Signaling for help is more appropriate for devices like flares or radios, cleaning the boat relates to maintenance products, and storing emergency supplies pertains to items like first aid kits or survival gear. Hence, the emphasis on the fire extinguisher's function in extinguishing fires and promoting safety is what makes this response the correct choice.