Andy is Rob’s older brother, characterized by his strong, outdoorsy physique and close connection to the family farm. He initially plans to take over the farm but instead chooses a life at sea after Rob decides to stay.

Ruth is the neighbor’s daughter, initially in love with Andy, who becomes enamored with Rob’s poetic dreams of adventure. Her choices heavily impact the Mayo brothers' lives and the course of the story.

Mary is the young daughter of Rob and Ruth, who shares a close bond with her father. She is perceptive of her parents’ emotions and serves as a unifying element in their relationship.

Kate is the mother of Andy and Rob, who supports her sons and hopes to mend family tensions. Her nurturing nature contrasts with her tendency to overlook the seriousness of her family's situation.

James is Andy and Rob’s father, who shares a strong resemblance to Andy. He has high hopes for his sons, particularly Andy, and his initial disapproval of Andy’s choices affects their relationship.

Mrs. Atkins is Ruth’s widowed mother, whose critical nature contrasts with her covert financial support of the farm. She is a staunch believer in free will and often makes blunt, harsh remarks.

Captain Scott is the maternal uncle of Rob and Andy who invites Rob to sail with him, a decision that impacts Andy and Rob’s futures. He is a seasoned sailor with a lively personality.

Doctor Fawcett is a specialist who is brought to examine Rob and provides a significant diagnosis regarding his health condition. His prognosis has profound implications for the family.

Ben is a farmhand whose decisions reflect the larger community’s ridicule of Rob’s farming struggles. His departure signifies Rob’s challenges in managing the farm.