The main character of the novel is Max Morden, an upper middle-aged writer who has recently suffered the loss of his wife Anna. Max narrates the novel and all other characters are seen through him. Max is a haunted narrator, haunted by the memory of his wife and their life together and by boyhood memories of recollected loves. In childhood, his romantic imagination borders on the literary. He describes the Graces as "Gods" of the Greek and Roman Pantheon, devours stories of the same, and even refers to his childhood sweetheart Chloe as "Pan"-like. At times morose, at times furious, we see a very unstable narrator in Max. Max's main goal is to express, via words, a life profoundly affected by the loves of two principal women and life spent near the sea's pounding presence.

Anna is Max's recently deceased wife. Max met Anna at a party in London one hot summer's afternoon. She is generally a larger proportioned woman, and what strikes Max most is her dark hair and her scent. Max describes the courtship with Anna and the acquaintance with her father in mythical and fantastical terms, where everything shimmered and nothing seemed real. Concerning their marriage, Max muses that what Anna proposed was not so much marriage as the chance to fulfil the "fantasy of myself."

Chloe Grace is Max's first girlfriend with whom he shares his first kiss. Chloe has a brother Myles. The two are strikingly alike and most often go about in shorts and bare feet. They play together, swim together, and their relationship changes over the course of their friendship. What began simply enough turns into a boy's first strong attraction to the female sex.

Claire is Max's twenty-something daughter. She is too tall, stark, and her rusty hair is usually unkempt around her freckled face. Max admits that she is not beautiful, but revels in her strong will and the fact that she is very bright. Max thinks she would have been more successful if she had not been waylaid by a recent ex-boyfriend who had her set aside scholarly pursuits for ones of a more philanthropic nature. Chloe keeps Max grounded and checks in to see how he's doing from time to time.

Other minor characters include Myles Grace, Mrs. Grace, and the many varied characters that come and go on the stage of The Sea. Myles is Chloe's brother and another playmate of Max's when he visits the sea as a boy. That Myles appears to have webbed feet is another allusion to Max's obsession with classical gods and goddesses. At first Max falls in love with Mrs. Grace and her sensuous look in a bathing suit. Later, however, Max transfers his love to her daughter Chloe, and Mrs. Grace becomes another fallen goddess in his youthful pantheon.