A Czech man is in hospital with serious spinal injuries after diving into a Sydney rock pool.
Police say they arrived at Dunningham Reserve in Coogee in the early hours of Saturday to find a "naked, hysterical" woman trying to help her friend out of the water.
It's believed the 30-year-old Czech national dived in to the rock pool about 2am (AEDT) and hit his head before becoming wedged between a rock ledge and the handrail of the pool stairs.
He was conscious but almost entirely submerged when emergency services arrived.
Paramedics and police rescue officers had to stabilise the man in the water before he could be moved onto a spinal board.
He was then treated on a rock platform for a full hour before he could be carried to a waiting ambulance.
The man is now in St Vincent's Hospital in an induced coma.
