When the poet says that the Mariner blessed the snakes "unawares", he is indicating that the Mariner blessed the snakes "in his heart". Coleridge's words appear to have been chosen to emphasize that the blessing was not something contrived, not an action done consciously for the purpose of achieving forgiveness. The Mariner has experienced a true change of heart, and when this change is effected, as evidenced by his ability to appreciate the beauty of the natural world, the spell which binds him begins to break. The Mariner discovers that he can now pray, whereas before, after he shot the albatross, he was unable to do so. Reconciled once again with God and nature, the Mariner is released from his punishment, and the albatross, which has been suspended as a symbol of his transgression around the Mariner's neck, falls off from where it hangs and tumbles into the sea (Part 4).