Gwinnett County fire Capt. Tommy Rutledge says three people - two adults and a child - were on the boat in Lake Lucerne. Somehow the adults went overboard.
Authorities say the woman surfaced and was rescued using a throw rope bag.
The man came up briefly but then went back under. Authorities lost sight of him.
The adults are friends and the 10-year-old child is the woman's son. Authoriites haven't released their names.