Final answer:
An ignition safety switch is a safety device on powerboats and PWCs that shuts off the engine if the operator is thrown off, preventing injury or damage.
Step-by-step explanation:
An ignition safety switch for most powerboats and personal watercraft (PWCs) is a device designed to turn off the engine if the operator is thrown from the helm or falls off the PWC. This safety feature, often referred to as a kill switch, typically involves a lanyard that is attached to the operator's body or life jacket and connected to the switch. If the operator is displaced from their position, the lanyard pulls the switch, and the engine is immediately shut down, preventing the boat or PWC from continuing under power and potentially causing injury or damage.