What is the main function of fire extinguishers on a vessel?

The main function of fire extinguishers on a vessel is to put out fires. Fire extinguishers are critical safety equipment designed specifically to suppress and extinguish different types of fires that may occur onboard. They are equipped with various extinguishing agents that can effectively combat flames, thereby minimizing potential damage, protecting lives, and preventing the spread of fire in a confined vessel space. Each type of extinguisher is formulated to tackle specific classes of fires, such as those involving flammable liquids or electrical equipment, which is vital in the unique environment of a vessel where safety is paramount.

In contrast, the other options listed do not align with the primary purpose of fire extinguishers. Keeping an area cool is not a function they serve, signaling for help is typically done with other equipment like flares or radios, and preparing food safely is unrelated to fire extinguishers' role in fire safety. This understanding emphasizes the importance of being well-equipped for emergency situations occurring on a vessel.