RedactedNarrative: Since both passengers on board were deceased and there were no witnesses, some of the information is unknown. What is known is:
  
  Passenger 1, told a witness that he was working on the generator. He went to get parts. It appeared the impeller was changed. There was one empty package and an unopened package of an impeller. 
  Witnesses stated vessel 1, returned from a boat ride, docked, left their dog on board and were meeting friends around 1700 on 6-30- 2018. 
  
  Both neighboring docked vessels stated that both passengers on vessel 1, returned around 1930 on 6-30-2018 and went inside after brief conversations. That was the last time both passengers were heard from or seen. 
  
  Witness 1, stated in the AM he noticed vessel 1, was hooked to shore power and the generator was running. Witness 1, went to check on vessel 1, passengers. When he looked inside he saw them lying on the floor, so he called 911. 
  
  Fire department tested the cabin area and detected very high levels of carbon monoxide. 
  
  The generator was examined. The exhaust had gotten hot at some point. The main exhaust hose was deformed and had a 1.5 -2 inch crack and several other small cracks and holes that were leaking exhaust and exhaust water.