RedactedNarrative: On 6/19/2016 I was en route to Alcova Reservoir when I received information over the radio that there was a possible drowning at the reservoir.  At this point I was informed that an individual had gone into the water and had not resurfaced for approx 20 minutes.  Upon my arrival at the reservoir I spoke with County Officer#1, from his patrol boat and was given information that the individual was still in the water and I could see the Natrona County Dive Team in the water searching.  At this point I launched our Game and Fish boat along with Warden#1, and assisted the county units with the search.  At approximately 1500 hours I along with Warden#1 made contact with the boat from which the victim voluntarily jumped off of without a life jacket to swim.  The purpose of this contact was to simply gather preliminary facts and contact information for all on board.  After the initial contact we approached the boat again and asked the operator, Operator#1 to meet us on shore so that we could conduct an interview.  The occupants of the boat stated that they had been out on the lake during the morning hours and then they went to the Alcova Marina for brunch at approximately 11:00 am.  During this time, Passenger#1 ordered and ate half of a breakfast burrito along with 5 shots of fireball whiskey.  At the conclusion of lunch, Passenger#1 paid the tab and they all boarded the boat and headed towards Fremont Canyon.  At the point where they were almost to the mouth of the canyon, they stopped the boat to try to hook up the blue tooth for their radio on the boat.  At this time, all three members of the boat stated that Passenger#1 tried to convince Passenger#2 to jump in the water with him.  When he declined, Passenger#1 voluntarily jumped into the water.  They stated that after approximately 5-10 minutes of treading water/swimming near the boat, Passenger#3 asked Passenger#1 if he was ok?  Almost immediately after this, Passenger#1 looked as if he was going to swim towards the boat when he abruptly sunk.  After seeing this, Passenger#2 jumped in to try to rescue Passenger#1 unsuccessfully.  Other witness accounts from campers and boaters on shore state a similar record of events.  However, one consistent thing from witnesses was that they all mentioned a lack of emotion from the boat passengers in the minutes leading up to Passenger#1 going under and the minutes after.  They stated that there was no screaming, or yelling for help, which all thought to be odd.  After approximately 4-5 hours of looking, the search was suspended because of higher winds and water visibility.  The next morning, 6/20/2016, we reconvened at the reservoir along with the Natrona County Sheriffs office and their dive team.  On this day we hooked up a side scan sonar to our patrol boat and with assistance from a member of the dive team began working a North-South Grid.  On our 1st pass, we detected an image that looked like a body along the bottom.  Upon seeing this, we marked the spot with a buoy and made several passes to ensure we had a reliable image.  With confidence about what we saw, we sent the dive team into the water and they were able to recover the body of the victim.