What is the meaning of the metaphors Creon uses in lines 538-542? What do they imply about how he will treat Antigone?

The metaphor that Creon uses refers to his authority in the country. This implies that Antigone is in his hands and that he can treat her any way he wants.

Explanation:

The metaphor that Creon uses means that he is the captain of the country, the sovereign who commands and demands and everything is under his control, for that reason, he can do whatever he wants and Antigone has to obey. Furthermore, he can punish Antigone for disobedience in any way he thinks is fair and in the way he imagines because no one will be able to stop him.