RedactedNarrative: Witness1 who lives on the south end of Lake Sonoma reported that he witnessed the victim rowing his boat past his dock going toward the SE end.  He stated that he witnessed victim fishing in this location, off his boat.  He stated that a short time later, he noticed stuff floating in the water and it looked as if the boat was upside down or going under the water.  He stated he did not see anyone around at that time.  Witness1 confirmed with his neighbor that he was seeing thing floating in the water as well and that he witnessed the boat go under the water.  This is when he called 911. He provided law enforcement with a general location to search, which proved to be accurate after the recovery of the victim.  Victim and vessel were located in approximately 11 feet of water.  He was not wearing a life preserver, but a cushion type life preserver was found floating in the water near the scene.  Family members reported that the victim suffered from congestive heart failure and may have had a heart attack.