RedactedNarrative: Pre-accident: 
  v1 was sitting in the cradle of the lift station located behind the residence of the owner/operator. The vessel had been lowered into the water. Both subjects were on the vessel to perform cleaning/maintenance and were standing inside the cockpit area of the vessel. The operator was situated forward of the occupant near the helm of v1, while the occupant was situated about midship nearer the engine compartment. 
  
  Accident: 
  after engaging the engine compartment ventilation blower system, the operator started the vessel's gasoline powered engine. Both v1 operator and occupant stated that the engine was "idling rough" at the time. V1 operator momentarily reached toward the helm and turned the blower system switch to the "off" position. Immediately upon doing so, an explosion occurred within the engine compartment, resulting in a flash fire. 
  
  Post-accident: 
  both v1 operator and occupant suffered 2nd and 3rd degree burns on their extremities and back area as a result of the flash fire created by the explosion. Neither person was ejected from the vessel or rendered unconscious. Both subjects were able to exit the vessel and seek help on their own. V1 operator stated that he attempted to cool the engine compartment with a garden hose prior to departing the vessel. 
  
  Post accident examination of v1 by this officer would indicate that the fire was contained within the engine compartment and no other parts of the vessel received any noticeable damage. However, certain external engine components did receive considerable heat damage as a result of the fire. 
  
  Although the vessel did appear to have all of its required safety equipment onboard, none was utilized. A serviceable b-ii portable fire extinguisher was observed on the boat dock, but it had not been deployed as evidenced by the safety pin being engaged and the pressure gauge reading "full charge." there were no known independent witnesses to this accident. 
  
  occupant was initially transported by ambulance to lee memorial hospital in fort myers for evaluation. Due to the severity of his injuries, he was later airlifted to tampa general hospital that same afternoon. He reportedly suffered 2nd and 3rd degree burns over 10% of his body to include his hands, arms and legs. 
   
  owner/operator was initially transported by ambulance to lee memorial hospital in fort myers for evaluation. Due to the severity of his injuries, he was later airlifted to tampa general hospital that same afternoon. He reportly suffered 2nd degree burns over 21% of his body to include his hands, arms, legs and back.