RedactedNarrative: AT APPROXIMATELY 0430 PM, UNIT 1 TOOK FUEL AT CONWAY MARINA.  UNIT 1 CAME TO CONWAY MARINA TO WORK ON A FUEL PROBLEM ON A NEW PURCHASED VESSEL.  AFTER FUELING APPROXIMATELY 10 GALLONS, THE OPERATOR MOVED THE THROTTLES IN AND OUT OF GEAR AND TURNED THE KEY WITHOUT RUNNING THE BLOWERS.  FUEL VAPOR IGNITED CAUSING AN EXPLOSION AND FIRE.  THE OCCUPANTS SUSTAINED BURNS AS A RESULT OF THE FIRE.