A race starting device for personal watercraft includes a thrust diverter connectable to the watercraft comprising a tube having an intake end adapted for alignment with the discharge nozzle of the watercraft, and a discharge end that is displaced from the intake end by a bent section of the tube to divert water flow from the water craft and thereby inhibit forward propulsion thereof until released. The diverter has the effect of deflecting the thrust from the watercraft and thereby inhibiting its forward propulsion. A quick release mechanism is also provided to releasably secure the thrust diverter to the watercraft. The release mechanism may be controlled by the watercraft operator to selectively release the device and allow the watercraft to thrust forwardly, leaving the starting device behind. Groups of the thrust diverters and quick release mechanisms may be provided on common frames for group starts. In one, a single quick release mechanism is provided to simultaneously start several racers.