In the novel "The Cay," there are several characters but the only characters that we get to know very well are Phillip Enright Jr, an eleven year-old boy. The other main character is Timothy, a elderly black man who helps Phillip when their ship is sunk by the German's. They land on the cay (island) and Timothy teaches Phillip how to survive.
The story also mentions Phillips mother, father and one of Phillips friends. These characters are not fully developed although we do get a sense of Phillips father being brave and patriotic. His mother is a negative frightened woman who complains constantly.
The characters in the book that I can recall are, Timothy, Timothy's mother, Phillip, and Phillip close friends/parents.