Swimming boy injured on rocks.
Rescue services were called to Cold Knap Point, Barry, Vale of Glamorgan, at around 7pm on Friday after reports of two boys struggling in the sea.
The two youths were spotted entering the water and starting to swim towards the outfall pipe.
Onlookers noticed one of the boys struggling and the other trying to rescue his friend but getting into worse difficulties and called the Coastguard. The RNLI Barry Dock Lifeboat was launched.
A boarding boat was also sent out to where the boys had scrambled on to the rocks.
The pair needed expert assessment and were treated by the Barry Dock Lifeboat crew before both were taken to the University Hospital of Wales, Cardiff.
One was airlifted by RAF Rescue Helicopter and the other was taken by ambulance.
Both the boys were suffering from the effects of cold and some injuries.
Gerry Adams, the Volunteer Barry Dock Lifeboat press officer, said that the incident could have easily ended in disaster if it had not been for the early reporting by onlookers.
He also reminded members of the public that the outfall pipe is a working piece of equipment and is placed in a current area for a reason, and that it should not be used to challenge swimming prowess.
When they arrived on the scene in the boarding boat, volunteers Dean Caldwell and Dave Brookes said it was like a repeat feeling of a similar incident last year that had almost ended in tragedy.