Thou counterfeit'st a bark, a sea, a wind; For still thy eyes, which I may call the sea, Do ebb and flow with tears; the bark thy body is, Sailing in this salt flood; the winds, thy sighs; Who, raging with thy tears, and they with them, Without a sudden calm, will overset Thy tempest-tossed body." What is the extended metaphor in these poetic lines?

In William Shakespeare's Romeo and Juliet (Act 3, Scene 5), Capulet and the nurse enter the stage and he starts talking to Lady Capulet about how she cries nonstop. She compares her and her little body to a ship, the sea and the wind. He goes on to say that if she doesn't stop crying soon, her raging wind (sighs) and the sea (her eyes overflowing with tears) are going to sink her ship (her body).