Water, water, every where, And all the boards did shrink; Water, water, every where, Nor any drop to drink.
Why it works
These four lines fulfill the essence of narrative poetry: they thrust a character into a specific, desperate situation that makes you feel the weight of their reality. The ballad meter, with its alternating tetrameter and trimeter, along with the repeated refrain, pushes the story ahead while trapping both the Mariner and the reader in the same relentless cycle. This repetition isn't just for show; it embodies the psychological snare from which the character can't break free. Story, image, and form work together seamlessly in this piece.