RedactedNarrative: VESSEL #1 WITH TWO OCCUPANTS ON BOARD WAS ATTEMPTING TO START ENGINE AT BOAT RAMP SHORTLY AFTER FUELING. Fuel VAPOR IN THE ENGINE COMPARTMENT IGNITED CAUSING AN EXPLOSION AND EJECTING  BOTH OCCUPANTS. BOTH OCCUPANTS WORE PFD'S AND CLAIMED INJURY. OPERATOR WAS EVALUATED AND RELEASE. OCCUPANT #2 WAS ADMITTED WITH A BACK FRACTURE. VESSEL #1 WAS BURNED BEYOND REPAIR, TOTAL LOSS.