RedactedNarrative: Small fuel leak in bilge. Fumes ignited while underway causing one person to be ejected.  All others jumped off and vessel burned completely.
  
  On Thursday, October 29th, 2015 at approximately 1400 hours, Michigan vessel MC6873TP, a 25ft Baja inboard/outboard, launched bay side of mile marker 95 in Key Largo, FL.  The vessel was just fueled with about 60 gallons.  The owner/operator smelled gas fumes in the bilge, so he used the blower to vent the bilge for about 5 minutes before starting the vessel.  After no smell of the fumes were detected, Operator turned the engine on and idled away from the boat ramp.  At approximately 1455 hours, there was a small explosion near the front hatch towards the bow, where Occupant was standing.  Occupant1 was ejected from the vessel into the water from the explosion, but was uninjured.  Right after the small explosion, Operator told the other 3 occupants to jump out of the boat.  One person quickly grabbed PFD's and a bag and jumped off of the vessel.   Another person received a small laceration to his left ankle while jumping off the boat, and one received minor burns to his right side and leg.  A good Samaritan picked up all five occupants and took them to shore.  Shortly after they were picked up, a large explosion occurred, engulfing the boat in flames.
  
  Some areas of the port side of the vessel had burned to the waterline, so at 1550 hours, the vessel sank completely.  After the fuel burned off the surface of the water, the flames extinguished.  Operator contacted Sea Tow Key Largo to remove the vessel from the bay bottom. 
  
  The facts that the fuel vapors did not ignite when the engine was started, proper venting was performed, and ignition of the fuel vapors occurred during use suggests there was a fuel leak somewhere in the bilge. The initial small explosion was caused by the fuel vapors igniting, whereas the second large explosion was caused by the fuel in the gas tank igniting.
   