Three children have been rescued as they were swept out to sea near Bude.
Off-duty lifeguard Ross Hamley battled through a 4ft (1.2m) swell to reach the girl and two boys who had got out of their depth at Northcott beach.
The children, aged between seven and 12, were safely brought back to shore but the RNLI warned it could have been more serious.
Their parents, who were further up the beach, did not realise what was happening, it added.
Mr Hamley said the children were about 131ft (40m) offshore and were struggling in the choppy conditions.
"One of the boys had lost his bodyboard so there were two of them clinging to one board with surf crashing over their heads.
"The girl was even further out and the waves and strong current were making it difficult for her to get back in.
"I jumped straight in and waded out to reach the boys where I was able to quickly pull them safely into shallower water so they could stand up and make their own way back to shore.
"I then went back in and had to swim out to reach the young girl, I put her on her board and used a wave to get us both back to shore."
The children were shaken, but unhurt.
"I was especially concerned that their parents were at the top of the beach and completely oblivious to what was happening," Mr Hamley added.
"The three children were just lucky I was walking past as it could have been a much more serious situation."