A teenage girl was taken to hospital after four children got into difficulty in the surf line on Benllech beach.
The RNLI's inshore lifeboat from Moelfre, the Enfys 2. was sent out on Tuesday after the group found themselves stranded.
When the three-strong crew arrived, they found the children had been helped back to shore by members of the public who had entered the water to help.
But one teenager needed urgent medical attention and was given first aid by the lifeboat crew and local coastguards from Moelfre.
The girl was conscious and alert but was taken by ambulance to Ysbyty Gwynedd in Bangor for a further assessment, while the other children - and their Good Samaritan - were checked over and treated for minro cuts and grazes.
The helm at Moelfre lifeboat station said the children were "very lucky to get out of the challenging conditions relatively unscathed".
Mike Hughes-Roberts said: "There was 1.5 - 2m breaking surf on the beach which had overwhelmed the children - fortunately, bystanders had seen it all unfolding and called for help straight away."
"If you’re planning on venturing out on, or into the water, please consider the weather conditions, have means of calling for help and ensure you let someone know your plans."


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