Jerry
Jerry is an eleven-year old English boy on vacation with his mother on a beach they have frequented in the past. Jerry's mother is a widow and is sometimes overprotective, sometimes not protective enough, of her son. Jerry attempts to make friends with some older boys on the beach, but they ignore him after discovering he is childish. Jerry is jealous of the older boys—he watches them as they swim through a rock in which there is a narrow underwater gap. In an attempt to become equal to them, he begins to persistently practice holding his breath so that he too may swim through the rock. He is determined to be able to hold his breath for a sufficient time so he can accomplish this feat. For Jerry, without a father and rapidly approaching adulthood, this challenge represents his coming-of-age, and with his success also comes independence from his often overprotective mother.

Mother
The mother is an anxious widow who takes her son, Jerry, on vacation. Her pale arms indicate that she is unused to outdoor activity, and she seems uncomfortable throughout the entire story. She worries about being too possessive, or not protective enough. She buys her son goggles and lets him play where he wants, until he comes back with a bleeding nose or pale from swimming underwater and she forces him to stay with her on the "safe beach" for a day. Jerry leaves the next day and risks his life while the mother rests on the tourists' portion of the shore. She and Jerry are alternately distant and extremely close, and the tension between her authority and her son's freedom cuts through the entire story. She is a widow and must take care of her son by herself. Her anxieties over Jerry's freedom and protection may indicate the difficulties inherent in raising her son without a father figure.