RedactedNarrative: Operator had beached the PWC on the east shore line of the St Croix River after traveling from the Prescott area to 1/2 mile north of Kinnckinnic State Park.  The operator added fuel to the PWC because it had been acting up and he thought that maybe it was low on gas.   Immediately after he finished fueling up he tried to start the PWC and the PWC "Just exploded" ejecting both the driver and the passenger off the PWC.