How is the speaker “at sea” both literally and figuratively? Do you find the sea to be an effective symbol?

THe speaker is literally at sea in a boat. He is metaphorically at sea because of his isolation and loneliness. The speaker of the poem describes his feelings of alienation in terms of physical privation and suffering: "My feet were cast / In icy bands, bound with frost, / With frozen chains, and hardship groaned / Around my heart." The cold that seizes his feet, immobilized in the hull of his open-aired ship while sailing across a wintry sea, corresponds to the anguish that clasps his mind. "Alone in a world blown clear of love,"