RedactedNarrative: Owner/Operator of vessel #1 had stopped about 300 yards from shore because all 4 men in boat wanted to swim.  Boat was adrift in calm water when victim jumped into 30' depth.  He began to struggle for unknown reason, but others couldn't save him before he went down.  Victim was recovered 18 hours later by Sheriff Department dive team.  A preliminary investigation suggests accidental drowning.  Victim was not wearing a live jacket.  No other injuries or damages were reported.