Most of the characters in The Dolphins of Pern are familiar to McCaffrey's readers. The main families in this story are Jayge and Aramina from Renegades (1989), who are the Lordholders of Paradise Cove. Readis is their oldest son. Their closest neighbors are Alemi and Kitrin, the Masterfisher of the hold. Alemi, introduced in Dragonsong (1976), is Menolly's older brother. The newest character is T'lion, a bronze dragonrider from Southern Weyr. He has responsibilities for transporting various people, and is drawn into the investigations of the dolphins.

One of the essential plot complications of the novel is the difficult relationship between Aramina and Readis.

Their relationship is loving and respectful, as should be between mother and son. However, Aramina has some specific aspirations for Readis: to be both Lord Holder after his father and to be a dragonrider, as she was too afraid to be. She is quite upset by...