RedactedNarrative: Officers while on a routine boat patrol heard a distress call about a vessel that had caught on fire at the breakwater.  They saw a cabin cruiser adrift in a mooring field on fire.  Harbor master's department vessel were on scene and were rescuing occupants of the burning vessel from the water.  Officers elected to tow the vessel away from the other moored vessels and fuel dock at wharf.  They anchored the vessel about 20 feet of water.  At this time the USCG arrived and began pumping water onto the fire.  Vessel burned to the waterline and then took water over the starboard quarter and sank.  Vessel was a total loss and one of the occupants suffered injury.  10/1 waiting for investigation to be complete for cause of accident and received victim's statement to determine what occurred prior to officer's coming on to scene.  10/1/14 Operator and victim were leaving harbor and were having issues keeping the port engine running.  He gave it throttle in neutral, put it in gear and the engine hatch blew up and the vessel exploded.  Preliminary cause is that improper maintenance was cause to this accident.  The operator had maintenance done the week before.   A joint inspection of the engine and vessel in scheduled for 10/14 and more information to follow.   
  
  11/19 Accident investigation is complete.   
  
  According to statements from the operator and victim.  Once underway the victim was lying on a bench inside the cabin due to the fact he was hung over and heard the engine made  a straining noise prior to the engines shutting down.  The operator tried to figure out the problem by adjusting the throttle system and once he felt he did he attempted to start the engines and the explosion occurred.   Just 15 seconds prior to that occurring the victim noticed a 5 gallon gas container on the floor and if his legs had been dangling instead of laying flat his injuries would have been much worse.  The explosion sent victim flying in the air approximately 3 feel above where he was laying.  He landed dazed and confused and notices he was injured and the cabin engulfed in flames.  Operator opened the cabin and advised victim to exit immediately.  Once the fire began to consume the vessel they jumped into the water and rescued later by the USCG. 
  
  Investigating officer determined this incident to be accidental in nature with no apparent manufacturing defect, criminal intent, fraud or foul play but however he cannot rule out the possibility of a maintenance mishap at this time.