A safety system, which stops the motion of a boat or other craft when a person falls off the craft, is comprised of a wireless transmitter carried by the person, a receiver-controller, an actuator, and a rotary on-off switch, such as a common ignition switch. When the person falls off and moves away, the diminution in wireless signal causes the electromechanical actuator, attached to the control panel, to rotate the key which is in the ignition switch. A linear actuator either pushes or pulls on the grip portion of the key, with or without the use of an end cap which receives the key grip portion, for better connection or mechanical advantage. The actuator stores manually input energy, to enable the use of a compact and low power solenoid type coil.