RedactedNarrative: THIS CRASH OCCURRED AFTER VESSEL 1 HAD JUST BEEN REFUELED.  OPERATOR 1 UNSUCCESSFULLY ATTEMPTED TO START VESSEL 1.  WITNESS 6 OBSERVED SMOKE EMITTING FROM THE BOAT WHILE OPERATOR 1 WAS TRYING TO START IT.  OPERATOR TURNED ON HIS BLOWERS AND ATTEMPTED TO START THE BOAT AGAIN WHEN IT EXPLODED AND CAUSED BURNS TO THE OPERATOR AND PASSENGERS.