Whilst waiting for the emergency services to arrive, Ethan was joined by others by the side of the river to give the man CPR – something he had learned at school.
Wrth aros i'r gwasanaethau brys gyrraedd, ymunodd eraill ag Ethan i roi adfywiad cardio-pwlmonaidd i'r dyn - rhywbeth yr oedd wedi'i ddysgu yn yr ysgol.