The 16-year-old boy suffered a “medical episode” in the surf at Mooloolaba Spit just before 11am Monday, a Queensland Ambulance spokeswoman said.

Lifeguards performed CPR on the teen before paramedics arrived and took the boy to Sunshine Coast University Hospital.

“We have been advising beachgoers to stay close to the shore and swim between the flags,” a Surf Life Saving Queensland spokeswoman said.

She said surf conditions at the Sunshine Coast had been rough with some flash rips and strong currents due to increased surf size.

Meanwhile Lifeguards at nearby Alexandra Headlands have rescued another two 16-year-old girls swimming in a rip outside the flags.