He couldn't break the front windows with the fire extinguisher so went around to the back and managed to break the car's back window.
The car was at 45 degree angle with the water halfway up the windows.
"I put my hand in and grabbed her hand but I couldn't pull her out. When I broke the window the water rushed in and the car seemed to go from a 45 degree to vertical.''
Mr Bibby said there was so many suitcases and containers in the back which made the rescue even more complicated.
"She had that much rubbish in the back all of it fell to the front on top of her.''
He reached into the car as far as his waist to try and get hold of her. "She was screaming, panicking and thrashing around...She couldn't get out because of suitcases in the way and it was dark and water rushing in and she was panicking...It's hard knowing which way to go, you know.''
The woman, who is 62, was screaming for help. "She was shouting, ` help me, help me I can't breathe get me out. There was only about a foot of airspace in the roof when we actually got her out.''
Mr Bibby said the car was gone within 30 seconds of her getting her out. "I was standing on the car and then there was nothing to stand on.''
Mr Bibby managed to pull her free by grabbing hold of her right arm with one arm and her hair by the other.
"I cut my stomach, my arm and hand on the glass but didnt even realise till I got home in the shower.''
On the boat back to the beach the woman, who was in shock, said she had got the pedals and gears mixed up.
This week's rescue wasn't his first - three years ago he saved a woman who had walked into the water fully clothed in almost exactly the same spot.
Constable Antony Hawkings arrived at the scene and he swam 40 metres to the scene to assist. The officer climbed onto the roof of the vehicle and helped Mr Bibby get the woman out of the car.
Rodney Police Area Commander Inspector Scott Webb says the woman would have drowned had it not been for the courage, determination and persistence of the two men.
"There's no chance that the female occupant would have been strong enough to break out of the vehicle and swim to safety. Mr. Bibby's actions with the assistance of Constable Hawkings meant this rescue was successful, compared with what could otherwise have been an absolute tragedy.''
The woman was taken to North Shore Hospital for observation and is receiving treatment.