THE PURPOSE AND USE OF A LANYARD
Your PWC will not start unless the lanyard is attached to the start/stop switch. The lanyard is there for your protection. PWCs are fun to drive with their quick acceleration and sharp turning ability. This also means that PWC operators inevitably end up off their vessel and in the water.
Always ensure that the lanyard is attached to your wrist, PFD or clothing before starting the engine. If you fall off the PWC, the lanyard will be pulled off the start/stop switch and the engine will stop immediately. The lanyard ensures that a "runaway" PWC does not endanger other swimmers or boaters. And, when the lanyard stops the engine, you won't have to swim so far to get back on for another ride.