The poem starts out on a ship; a crew pulls up a dead man and tosses him back overboard. The next stanzas weave together imagery from Moby-Dick, The Odyssey, the Bible, Lowell's experiences, early American history, and other Greek myths. In one section of the poem, the sailors murder the whale. The poem also describes a pilgrimage, which the narrator has complicated feelings about. The poem ends by reflecting on the ocean, God, and the creation of man.