The narrative follows Ralph Osborn, a young aspirant to the Naval Academy, through competitive examination, admission, and the routines of midshipman life. It presents drills, studies, customs, discipline, and the social dynamics of friendships and rivalries while highlighting a memorable geometric demonstration. Adventures at sea during summer practice include a man overboard and a boiler explosion, and shore episodes involve hazing, kidnapping, a court-martial and dismissal, followed by later reconciliations. Technical instruction, moral testing, and peer loyalty combine to trace the protagonist’s practical education and personal growth within naval service.