Thomas Scard sensed something was not right when he saw a small boat with five people on board in rough conditions at the Pumicestone Passage last month.
The 15-year-old was out in his tinnie catching live bait.
He said he approached the family to see if they needed help and they gave him the thumbs up that all was OK, but Thomas's instincts told him to stay nearby.
"Their boat was completely overloaded with three adults and then there [were] two children on the vessel as well," he said.
"So I hung around for a bit and eventually they pick up too much water, I can't remember how it happened but all I know is that they've flipped."
Thomas sprang into action, pulling the woman and a young girl to safety on board his boat.
He said the family members were frightened and battling treacherous conditions.
"I quickly drove over as fast as I could," he said.
"I pulled the little girl in and her life jacket wasn't even on properly and when she first hit the water, she was freaking out."
Onlookers watching the incident called triple-zero and a rescue helicopter and Coast Guard soon arrived to help.
Thomas honoured for his actions
Thomas said he has spent much of his life on the water and while he is not yet old enough to have a car licence, he is able to have a small boat, which gives him freedom.
The teenager was this week presented with bravery awards from the Caloundra Coast Guard, Sunshine Coast Council and state MP Jason Hunt for his heroic actions.
But Thomas said he was only doing what anyone else would have done in that situation.
"I just feel like I did what I needed to do and I just feel like I did what anybody else would have done," he said.
Caloundra Coast Guard Commander Roger Pearce said it was important to recognise the teenager's efforts on the day.
"He got three little awards and he was very chuffed," Mr Pearce said.
"He's a very nice young lad and he was just in the right place at the right time and it was over very quickly, but he did a wonderful job."
New Bribie Island bar officially named
Thomas is encouraging all recreational boaties to be careful in the area after the formation of the new coastal bar where the family got into trouble.
The state government has now gazetted the island breakthrough and it will be known as the Bribie Island Bar.
"If you go around the bar in any type of vessel, doesn't matter how big or small you should always be prepared," Thomas said.
"It you're seeking to have an adventure around that area, I'd give this advice, do you have life jackets onboard? is your vessel appropriate for the area? how much am I loading it up'."
The declaration of the new bar means anyone crossing it will be required to use life jackets.
The bar has been mapped and added to maritime charts by Maritime Safety Queensland.
