Another person nearby called for help after watching the woman, head down as she looked at her phone, stroll off the pier.
The young woman thanked rescuers when she was pulled out of the water 30 minutes after she took the plunge.
"When we brought her on board one of the first things she did was apologize and say sorry," Senior Constable Dean Kelly told The Sydney Morning Herald.
And she was remarkable calm.
‘‘She wasn’t splashing around too much. She wasn’t in a panic even though she was in the water for probably 20 minutes,’’ Kelly said.
The constable pointed out the woman was wearing a backpack that helped her float.
‘‘She wasn’t a good swimmer but she was floating OK, on her back,’’ he finished.
Luckily, someone in the Austrialian town of St Kilda saw her tumble and called police, who plucked her out of the water around 100 feet from the pier.
Cops say the woman still had the phone in her hand when she was pulled on-board.
On the bright side, how often can you tag Nemo and Dory in a Facebook post?