RedactedNarrative: Vessel 1 was anchored off of Rodriguez Key (Key Largo, Monroe County) inside of John Pennekamp State Park waters just outside of the no motor zone area marked by buoy R16.  Operator 1 tried to start the starboard outboard motor but the starter motor on the engine stayed engaged causing smoke to emit from the engine.  
  
  Operator 1 opened the center console hatch to shut off the batteries to kill power to the engine when the fumes inside the small compartment ignited and ejected Operator 1 in to the water.  
  
  The vessel, a rubberized inflatable rib, became fully engullfed in flames and  burned to the waterline where it sunk to the sea floor 5 feet below.  Operator 1 did not suffer any injuries.  There was a reported 80 gallons of fuel on board that either burned off or leaked out as there was no fuel remaining on board the following day post salvage.  USCG Pollution in Sector Key West was notified.  
  
  The starboard outboard engine starting motor become stuck in the run/start position causing it to fail and overheat (based on smoke coming from the engine).  
  
  When trying to kill power to the engines using the battery switch, gasoline fumes from the forward mounted fuel tank quickly ignited as the light breeze picked up the fumes which drifted straight to the smoking engine where the fumes ignited setting the vessel on fire and ejecting the operator in to the water and away from the flames.  Thus engine failure is the most likely cause of this vessel fire/accident.  The vessel was a complete loss.