Deputies said Christopher Johnson, 27, had been missing since Tuesday night around 7:30 p.m.
Johnsons body was found by a relative at about 2:45 p.m. Saturday afternoon near a family dock in Lake Lanier.
Investigators said evidence suggested Johnson went fishing there.
Authorities do not suspect foul play.
The Hall Sheriffs Office said Johnson had a history of medical issues that could explain how he ended up in the lake.