RedactedNarrative: Unit 1 was at dock and the occupants were boarding.  Occupant was holding the dock line.  The Op cut on the blower and had started the engine and Occupant 2 stated that as soon as she put her daughter in the boat and sat down the boat exploded.  The engine cover was blown on top of her.  Occupant 2 moved it and got 1 and they jumped in the water.  Occupant 3 and Operator also jumped in the water as well.  Operator was also suffered burns on arms and legs.