A Surf Life Saving NSW spokesman said the boy was believed to have struck his head on rocks and was knocked unconscious.
Two of the boy’s friends who saw the accident grabbed a nearby angel ring and jumped into the water to try to save him.
They dragged their injured friend onto a rock platform and alerted emergency services, the spokesman said.
Paramedics performed CPR on the boy, but he died at the scene.
Paramedics also treated a 16-year-old boy at the scene for injuries that were not life-threatening, police said. That boy was taken to Port Macquarie Base Hospital for treatment.
Police said they had been told a group of males were seen jumping from rocks into the water at the time of the accident. Police will prepare a report for the coroner.