RedactedNarrative: V1(21FT STINGRAY)WAS NOT VENTILATED LONG ENOUGH PRIOR TO STARTING.BUILT UP GASOLINE VAPOR IN V1 ENGINE HATCH IGNITED AND CAUSED SUBSEQUENT EXPLOSION AND FIRE.
  
  Based on my investigation I have concluded the following:
  The vessel had built up fuel fumes due to being almost out of fuel. The operator checked the oil but only briefly had the engine hatch up. Passengers 1 and 2 were in the stern of the vessel behind the driver’s seat both received minor burns (see injury supplement and photos). In the bow of the vessel were passengers 3-6. 
  Based on information gathered it appears the brief exposure to the air provided oxygen to the engine hatch and when the vessel was started the mix was ignited causing the explosion and  fire. Following the explosion all occupants jumped into the water and swam to safety. The vessel Operator was subsequntly issued a warning for no boater safety I.D.