The poem
To-night I saw three maidens on the beach, Dark-robed descending to the sea, So slow, so silent of all speech, And visible to me Only by that strange drift-light, dim, forlorn, Of the sun's wreck and clashing surges born.
Each after other went, And they were gathered to his breast-- It seemed to me a sacrament Of some stern creed unblest: As when to rocks, that cheerless girt the bay, They bound thy holy limbs, Andromeda.

Three dark-clad maidens...one after the other. The particular light of an ocean sunset. Are these "maidens" actually rocks swallowed by the rising tide? What's with the Latin name, and the allusion to Andromeda?