How does Aeschylus use imagery in Seven against Thebes?

Imagery based on ships and the sea appears throughout the play and shows up in several different ways. In this scene, in addition to Eteocles referring to himself as the captain of a ship, the Chorus refers to the attacks as waves crashing up against the walls of the city. The imagery in general represents a basic element of the Greek philosophy of existence: that human beings (i.e. the ship) have some freedom of choice, but ultimately their destinies depend upon the will of the gods (i.e. the ocean). This also relates to the theme of the play: that to go against the will of the gods, or to make them angry, is to risk destruction.