What is the main function of a kill switch on a boat?

The main function of a kill switch on a boat is to automatically shut off the engine if the operator falls overboard. This safety feature is crucial because it helps prevent accidents and potential injuries that could occur if the boat continues to operate without the operator’s control. If the person operating the boat falls overboard, the kill switch activates and cuts off power to the engine, allowing the boat to come to a stop. This reduces the risk of the boat running unattended in circles and possibly causing harm to the person in the water or others around.

The other options refer to functions that are not related to the primary purpose of a kill switch. For instance, increasing fuel efficiency, monitoring boat speed, and serving as a safety whistle are important aspects of boating, but they do not pertain to the safety mechanism of the kill switch, which is specifically designed to enhance boating safety by preventing the engine from running if the operator is not present on the vessel.