The ZSJL Water Motor Alarm consists of a turbine shell, a vane wheel, a transmission shaft, a dabber, a rocker arm, a clapper, an alarm seat and a support shaft etc.
They use all kinds of things from a backpack with a softball inside to a ball in a sock on the back to a shark fin type thing to alarms that ring when you roll on your back.
Investigators say they are now trying to determine whether the float's driver could hear the horn and whether the signal timing and synchronization were operating correctly.