He got the girl onto the board and grabbed hold of Mr Alapati, "hugging him like you would a baby".
"Another surfer came over, and just as that happened another big wave hit us and ripped the guy out of my hands. When I came back to the surface, he had disappeared," Mr Wilson-Haenga said.
"I was hugging on to him front on, so I could see his face. When you look at someone like that when they're just about gone ... if I had been on dry land I probably could have saved him," he said.
"I'm just so sad I couldn't bring that boy back."
Friends of the missing former Porirua head boy have posted prayers he will by found safe and well on Facebook.
"Prayers and thoughts with the Alapati Fambino," Luisa Tapusoa wrote yesterday. "Pray that you (Albert) be brought back home safely. Been at your house ever since the news took place keeping your mother company. 1 love brash [sic]."e;
The incident was one of four presumed drowning over the weekend.