Read the poem aloud: what do you hear?
It's a noisy poem, that's for sure. The sounds spit and sputter and crash into each other, just like the sea. Lowell uses several effects to make the poem sound like a voyage over rough waters. Let's break them down, shall we?
Alliteration
Whew, this poem is chock full of alliteration: the repetition of beginning consonant sounds in words. Alliteration gives the lines a kind of symmetrical energy, and can sometimes be a tongue-twister, like "steel scales" (23) or "waves wallow in their wash" (81). Just try to say that ten times fast.
Internal Rhymes
Internal rhymes are just words that rhyme in places other than at the end of each line, like in the middle or at the beginning. Sound confusing? Here's a line from our poem:
Seaward and seaward on the turntail whale (75)
Notice the rhyme inside the line? "Turntail" and "whale" give us an example of internal rhyme. These rhymes add to the music of the poem, and their unexpected quality—popping up from out of nowhere like a bump in our voyage through the poem's sounds—can help mimic bouncing along on the water.
Assonance and Consonance
Assonance is the repetition of vowel sounds, like the long E sounds in "Heaves" and "pier" in line 28: "Heaves at the roped-in bulwarks of this pier." Consonance, similarly, is the repetition of consonant sounds, like the S sounds in "past castled Sion" (124). Combined together, they add another level of symmetry to the lines as these sounds echo in the mind's ear (in you can picture that) as you read.
Lowell combines theses effects with meter and end-rhyme in nearly every line of the poem, so we're sure you can find countless more examples. But why? What's up with all this fancy-pants acoustic techniques? Well, in much the same way that the poem never settles into a set rhythm (check out "Form and Meter" for more on that), this poem also keeps us on our toes (or, you know, just stumbling around) on a sonic level. We get pleasing connections in sound from time to time, but never regularly enough to get our bearings. If you haven't read it aloud yet, give it a try, and you'll see what we mean when we tell you that the sounds in this poem are all about recreating some "rough waters."