 That ensures that if you take a wave or you roll your boat and you fall out of the seat, it'll kill the engine and your boat won't run away from you or your boat will pinwheel around you and potentially injure you, other mariners, or other vessels that are operating in the area. So if your boat has a little red tab next to the helm, it's important you attach it to your belt, your life jacket, and keep it on whenever the boat's moving. That'll keep you, your friends, your family, and the fellow boating public safe.