A 48-year-old man is in a serious condition after a boat engine explosion left him with multiple burns to his body.

Careflight’s rapid response helicopter was tasked to Castlecrag shortly after 9am this morning, landing at a sporting field in Northbridge.

It is understood the man jumped into the water before Ambulance crews arrived and provided initial treatment.

Ambulance paramedics then transported the patient to the helicopter, where CareFlight’s specialist doctor and critical care paramedic treated him for burns to multiple parts of his body.

Treatment was continued by CareFlight’s medical team as the patient was transported in a road ambulance to Royal North Shore Hospital in a serious condition.

Police were also on scene.