It's from T. S. Eliot's "The Wasteland":

      IV. Death by Water

    Phlebas the Phoenician, a fortnight dead,
    Forgot the cry of gulls, and the deep sea swell
    And the profit and loss.
    
        A current under sea
    Picked his bones in whispers. As he rose and fell
    He passed the stages of his age and youth
    Entering the whirlpool.

        Gentile or Jew
    O you who turn the wheel and look to windward,
    Consider Phlebas, who was once handsome and tall as you.

I get Phlebas mixed up with those lines from Shakespeare's "The Tempest", where we get the idiom "sea change":

    Full fathom five thy father lies,
    Of his bones are coral made,
    Those are pearls that were his eyes,
    Nothing of him that doth fade,
    But doth suffer a sea-change,
    into something rich and strange,
    Sea-nymphs hourly ring his knell,
    Ding-dong.
    Hark! now I hear them, ding-dong, bell.