Stanza 1
Speaking in the first person, an unidentified person describes watching a fully decked out warship crash into an iceberg almost as if by mad design. The speaker gives no indication of his position relative to the ship or the circumstances which allowed him to witness this tragedy, but since the poem is usually accompanied by the subtitle "A Dream" one can readily assume that his perspective is from within sleep and that the events described are not intended to be taken as actually having occurred. The ship sinks as a result of the mad crash into floating behemoth with the iceberg victimized only by an initial collapse of one-ton sized chunks of ice which proved to be enough to send the ship below the surface of the water.
Stanza 2
The second stanza presents an unexpected turn to the events just described. Essentially the entire the stanza—all 18 lines—are presented as the kind of damage assessment report one might expect to read regarding the ship. Instead, this report is an extensive catalog of the damage which the iceberg did—or did not—suffer. What is notable is that this report is scientific and not merely casual: jargon actually related to iceberg construction like ridges, gorges as the description of colored ice as glass-green are used to convey the extent to which the massive chunk of ice was inflicted with almost no damage from the ship at all. To this information is added the useful detail that the force of the collision between ship and ice was insufficient to cause any notable distress to nearby birds. More striking of all is that the long, thin icicles as well as much larger chunks of ice which seem precarious maintained their position, staying intact rather than breaking off in the aftermath of the ship sinking.
Stanza 3
The speaker considers the physical reaction of the iceberg in light of the complete opposition action of the ship by musing on its actual cold hardness in terms of it being emotionally cold and hard toward the tragic collision between the forces of nature and the best that man has to go up against it the speaker just witnessed. The berg is alliteratively described as a lumpish, lumbering, loiterer; its breath rising into the sky when the air grows warmer, but otherwise showing utterly inhuman indifference to the consequences of its own majestic presence.
