Authorities say the son, who is in his 20s, decided to go for a swim just after 4 p.m. Then, his mother went in after him.
Police received calls for a swimmer in distress. When they arrived, they found the two in the water around 75 feet out.
Police deployed two divers from a helicopter.
The mother was placed into the basket and raised up to the chopper. She was not injured, but taken to Coney Island Hospital to be checked out.
The son was reportedly combative and resistant to police while they tried to help him to shore. Two divers swam him in, and he was arrested. Charges are pending.
The mother will not be charged.