Symbolism, Imagery, Allegory
Quick: When is water not water? When it's the sea in Omeros. Walcott crafts this symbol very deliberately from his first invocation of Homer. Check it out:
[…] Only in you, across centuries
of the sea's parchment atlas, can I catch the noise
of the surf lines wandering like the shambling fleece
of the lighthouse's flock (II.ii.13)
If you've spent any time at the seaside, you can understand how Walcott makes the connection between the surface of the ocean and a written page: Those lines and wrinkles of waves remind the poet of scribblings on paper. But more than that, the lines of breakers also push Walcott to think epically about the fleecy flocks of sheep belonging to Polyphemus, the Cyclops tricked by Odysseus.
Walcott's literary imagination allows him to map his thoughts onto the landscape of the sea that surrounds his beloved island. The idea of sea as map also helps us to think about the connections the poet makes between the Old World and the New, and between the modern world in the Caribbean and the ancient one on the other side of the globe. It's like the sea is a kind of literary-historical connective tissue that holds Walcott's narrative together.
But the sea has an odd quality, especially for something that's supposed to be a text: It can't be physically marked in any permanent way. And yet Walcott wants us to see the sea as a durable transmitter of history. Hmm… It takes some work of the imagination to envision the ocean as a giant page in a story that is constantly being re-written, but our poet definitely thinks of it in this way:
It was an epic where every line was erased
yet freshly written in sheets of exploding surf
in that blind violence with which one crest replaced
another with a trench and that heart-heaving sough
begun in Guinea to fountain exhaustion here (LIX.i.296)
Can you see what he did there? By moving from the visual lines of the surf to lines of writing, Walcott immediately focuses us on a specific type of writing: epic poetry. The parchment with its lines becomes a nifty, short-hand way to link the visual experience of the sea with the poet's choice of genre. Best use of metonymy. Ever.
We can argue that the poem itself is a meditation on how an ancient, literary past affects our perception of the world around us. The figure of the sea as parchment highlights the role played by the natural world in the transmission of this artform from one culture to another—as people are moved across the sea, so, too, is their art. Or some of their art, anyway.
The poet is literally beckoned by the "book of the sea" to seek epic origins for his work: "A wind turns the harbour's pages back to the voice that hummed in the vase of a girl's throat: 'Omeros'" (II.ii.13). This call is the voice he can't get out of his head.
It's also the image Walcott can't get out of his mind when he thinks about his personal identity. His life is so caught up in the lines of his writing that parchment inevitably comes back when he begins his journey to the afterlife and thinks about his verse and purpose: "I could hear the crumpling parchment of the sea in/the wind's hand, a silence without emphasis,/but I saw no shadow underline my being" (LVI.ii.282). At the end of his career, the sea and the page—his two great loves—have the last words.