Billie said: “I was really scared and tried to swim back… but then I got really out of breath and really tired.

“I was floating on my back, trying to get my energy back… and then I started screaming for help.”

The 11-year-old girl, who has learning difficulties that may affect her memory, said she remembered the Swim to Live program., external technique from her swimming lessons.

Mr Reed said floating on his back gave the children a few extra minutes of survival as he swam about 20 meters (66 feet) to reach them.

He said: “I managed to grab her, calm her down and calm her down and then we headed towards her friend who was being helped by another person.”

Kate said she was unable to track down the other rescuer.

She visited Mr Reed at Mudeford Life Saving Station to thank him and hopes to raise £500 for the charity through an online fundraising page.