Typically we think of a man with, courage, muscular strength, skilled in hunting, and super masculine.
Mafatu's character was weak, fearful, did not like to take chances, and was profoundly disappointing in his father's eyes... so much so, that father stopped talking all together.
Mafatu's greatest fear was the main source of life in his village- the ocean. It provided the village people with the food they needed to live and thrive. But he was very afraid of the ocean and could not fish with the other men in the village.
As a result, he was chastised, made fun of that he will never be man enough to take care of a family of his own.
Tired of being picked on by the other people in the village, Mafatu takes off in a boat with his only friend, a dog. He is determined to prove his courage to the people in his village, especially his father.