RedactedNarrative: Operator noticed the PWC was running rough, stopped, opened front cover and seat did not see water or smell fuel.  Restarted and got on plane they guessed their speed at 15 MPH and then it exploded sending the operator over the handlebars into the water.  The PWC then caught fire and the other PWC that was with him attempted to use  the fire extinguisher, and another PWC was splashing water on it to put it out.