Jerry is an eleven-year old English boy on vacation with his mother on a beach they have neen to before. Jerry's mother is a widow and is somewhat overprotective, yet 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 quite childish. Jerry is jealous of them. In an attempt to emulate them, he begins to persistently practice holding his breath so that he too may swim through the rockthe older boys do.
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. She and Jerry are at times distant and sometimes extremely close, and the tension between her parenting and her son's freedom cuts through the entire story.
The characters are 11 year old Jerry and his mother, who are English, on holiday in a foreign country. The two characters struggle with Jerry's becoming an adult while still on the cusp of being a child. (Jerry's father is dead.)