Arnold uses a number of literary devices in "Dover Beach." In the fist stanza of the poem, the speaker invites the reader to listen to "the grating roar / Of pebbles" as the tide comes in, and in stanza three he describes "the breath / Of the night-wind." Both of these quotations are examples of personification, ascribing human traits to nonhuman things. When Arnold describes the "roar" of the pebbles and the "breath" of the wind, he is implicitly evoking human emotions through natural imagery. These are thus subtle versions of a technique known as the pathetic fallacy, a poetic form of personification that finds human feelings in the nonhuman.
Throughout the poem, the sea acts as a metaphor. This is made clear in the second stanza , where Arnold uses the ebb and flow of the sea's tides metaphorically to represent "the turbid ebb and flow / of human misery." This metaphor points to the speaker's rather pessimistic view of the world, as it suggests that, like the tides, human misery is both inevitable and natural.
Arnold also uses similes in the poem. For example, in the third stanza the speaker says that there was once a time when people had faith and that this faith was "like the folds of a bright girdle." A "girdle" is something which surrounds something else, and so this line is suggesting that faith surrounded the earth and was thus everywhere. The "bright[ness]" of the girdle also suggests the relative happiness associated with this faith.
In the final stanza of the poem, Arnold uses repetition, specifically anaphora, when the speaker says that the world "Hath really neither joy, nor love, nor light, / Nor certitude, nor peace, nor help for pain." The repetition of the negative "nor" emphasizes how desolate, hopeless, and bleak the speaker's view of the world is.