What metaphors does Haimon use to argue that Creon should be more flexible?

Even though Creon has ordered the death of Antigone, his son Haemon's intended wife, Haemon doesn't challenge his father directly or react emotionally. Instead, he approaches Creon reasonably and logically in order to persuade him to change his mind.
Haemon tells Creon that the gods have given mankind the gift of reason and that the wisest and most reasonable among them listen to the comments and advice of others, rather than believing that their own counsel is always best.

HAEMON: For whoso thinks that wisdom dwells with him,That he alone can speak or think aright,Such oracles are empty breath when tried.It is no reason never to yield to reason. The wisest man will let himself be swayedBy others' wisdom . . .

Haemon then uses two metaphors to support his argument. In the first metaphor, Haemon compares Creon to a tree in a flood. The trees whose branches yield to the flow of the torrent of water survive, but the trees whose branches refuse to yield are destroyed.

HAEMON: See how the trees beside a stream in floodSave, if they yield to force, each spray unharmed,But by resisting perish root and branch.

If Creon refuses to listen to the advice of others and stubbornly and unreasonably adheres to his own decisions, he will surely be destroyed.
In the second metaphor, Haemon compares Creon to a sailor who refuses to loosen the sails on his ship. The ship, symbolizing Creon's leadership of Thebes, will be overturned by the gale, symbolizing the harsh disapproval of the people of Thebes.

HAEMON: The mariner who keeps his mainsheet taut,And will not slacken in the gale, is likeTo sail with thwarts reversed, keel uppermost.

Unfortunately, Creon rejects his son's advice, which ultimately leads to his tragic downfall and to the deaths of Haemon, Antigone, and his wife, Eurydice.