Mr Faitaua was swimming at the west Auckland beach with his girlfriend, reportedly in "quite treacherous" conditions near rocks, when he got into difficulty at the northern end of the bay, to the north of Bethells Beach.
Mr Faitaua's mother Luisa spoke of her grief at the weekend as she stood vigil at O'Neills Bay with family and friends.
"My last words to him were 'be careful, son, that beach is dangerous' and then we said our goodbyes," she said.
Ms Faitaua, mother of three, said her son was "kind, gentle and quiet".
"He is always at home with us so we are very close to him. The whole family is very close-knit," she said. "He is such a loving boy."
Quiet and humble guy: missing swimmer Johnny Faitaua
Soon to be in his second year studying music at Massey University, Mr Faitaua was a talented keyboard and piano player.
"He loves what he does. It took him a while to find what he loves but once he found it, he knew he was on the right path," Ms Faitaua said.
Mr Faitaua's brother Phillip said on Friday: "It feels so surreal. You hear of these things happening to other people but you never think that something like this would happen to someone in your family. It is just a tragic accident."