Tress, whose given name is Glorf, is the protagonist of Tress of the Emerald Sea. A quiet, thoughtful girl at the beginning of the novel, Tress feels content to live out her life on the Rock in much the same way as she has her entire life. Unassuming, Tress never wants to impose on others, instead taking care of whatever she can for the people she loves. Tress gained her nickname because of her wild, flowing hair, which she often tries to restrain, embarrassed by its misbehaving and the attention it brings to her. Her hair and her relationship to it represent her innate sense of adventure that she has previously sought to quell.

Tress, like many male heroes in traditional adventure narratives, is a reluctant hero. Despite this, she learns to love life as a sailor, seeing the world and learning all that she is capable of. Though many traditional hero narratives center men, there are no limitations surrounding gender in Tress’s world. She is free to do as she likes, limited only by her own lack of self-confidence and her birth as a resident of the Rock. Tress’s inner conflict involves discovering her true identity, gaining self-confidence, and learning to ask for help.