On Clare Island, five-year-old Grace O’Malley cuts off her braid to challenge her father, the chieftain Eóin O’Malley, after he explains that she cannot join him on his galley, Niamb, because her long hair will get caught in the ropes. Despite her drastic action, Eóin still refuses, believing that girls don’t belong at sea, and departs with her older half-brother, Donal O’Malley. In defiance, Grace throws her severed braid at his ship.

Later, Grace’s mother, Maeve O’Malley, comforts her and advises her that she will have to force men to respect her. That night, Grace secretly listens as her parents argue. Maeve accuses Eóin of not telling Grace the truth that it’s considered bad luck for women to be at sea. Eóin admits that he lied about Grace’s hair getting caught in the ropes because he’s angered by her fierce love for it, which contrasts sharply with his son Donal’s fear of the water. Maeve persuades him to take Grace on a voyage, reminding him that their daughter was born during a powerful storm and that she possesses a deft command of the water. Overhearing this, Grace is emboldened.